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J^ EARTHQUAKE PLANNING SCENARIO 



5 S 



For a Magnitude 8.3 Earthquake 

on the San Andreas Fault 
in the San Francisco Bay Area 



EARTHQUAKE PLANNING SCENARIO 

For o Magnitude 83 Earthquake on the Son Andreos Fault in 
the San Francisco Bay Area 
MIC INTENSITY DISTRIBUTION 




CALIFORNIA DEPARTMENT OF CONSERVATION 
DIVISION OF MINES AND GEOLOGY 




SPECIAL PUBLICATION 61 







- rry 
NOV 2 

CALIF. 



THIS REPORT WAS PREPARED FOR THE 
GOVERNORS EMERGENCY TASK FORCE ON EARTHQUAKE PREPAREDNESS 
AND IS FOR EMERGENCY PLANNING PURPOSES ONLY 





STATE OF CALIFORNIA 

EDMUND G. BROWN JR. 
GOVERNOR 

THE RESOURCES AGENCY 

HUEY D. JOHNSON 
SECRETARY FOR RESOURCES 

DEPARTMENT OF CONSERVATION 

JAN DENTON 
DIRECTOR 



DIVISION OF MINES AND GEOLOGY 

JAMES F. DAVIS 
STATE GEOLOGIST 



u e*<^ 






EARTHQUAKE PLANNING SCENARIO 

FOR A MAGNITUDE 8.3 EARTHQUAKE 

ON THE SAN ANDREAS FAULT IN THE SAN FRANCISCO BAY AREA 



By 



James F. Davis, John H. Bennett, Glenn A. Borchardt, 
James E. Kahle, Salem J. Rice, and Michael A. Silva 



1982 



California Department of Conservation 
Division of Mines and Geology 



Special Publication 61 



Prepared for the Governor's Emergency Task Force 
on Earthquake Preparedness 



ii 



PREFATORY COMPARISON 

OF THE NORTHERN AND SOUTHERN CALIFORNIA 

EARTHQUAKE PLANNING SCENARIOS FOR THE SAN ANDREAS FAULT 



To be effective, emergency-response plans must reflect the general conse- 
quences of an anticipated earthquake within a particular region. Therefore, 
emergency-response plans are not checklists of generalized conditions that 
must be dealt with; rather they are systematic strategies that are closely 
related to the special circumstances of the area for which they are designed. 
The emergency-response plans required to be effective in coping with a north- 
ern California magnitude 8.3 earthquake on the San Andreas fault are signifi- 
cantly different from those appropriate to a similar sized earthquake on the 
southern California segment. This planning insight is evident from a compar- 
ison of Special Publication 60 (southern California) and Special Publication 
61 (northern California), two planning scenarios that have been developed by 
the California Division of Mines and Geology (CDMG). Since these scenarios 
are identical in scientific approach and methodology, genuine contrasts 
between patterns of regional consequences can be identified. 

The discussion which follows highlights the principal contrasts between 
the effects of magnitude 8.3 earthquakes on the San Andreas fault segments in 
the vicinity of Los Angeles and of San Francisco. These scenario earthquakes 



in 



will be similar in size and location to the 1857 earthquake in southern 
California and the 1906 earthquake in northern California. 

The general consequences of these scenario earthquakes in both southern 
and northern California will be to overwhelm existing capabilities of coping 
with significant interruption of ground transportation, communications, water 
supply, sewage treatment, electricity, and pipeline distribution of natural 
gas and petroleum. Existing emergency-response capabilities will be taxed 
beyond their limits by the combined effect of regional damage to all the 
important lifelines upon which the metropolitan areas depend. These circum- 
stances will compound the problem of providing medical aid and search-and- 
rescue services to the stricken areas. 

In southern California, the strategy for bringing supplies and assistance 
into the Los Angeles region following the earthquake should emphasize ground 
transportation, which will probably be possible by freeway and by railroad 
from San Diego. In addition, air transport into the area will be feasible 
for large cargo planes at a number of the large airfields if auxiliary power 
supplies are available to maintain radio communications, landing lights, and 
other requirements necessary to the operation. An effective distribution of 
materiel and personnel within this large metropolitan region will be a great- 
er challenge than access to the region from the outside. A major handicap to 
the effort to coordinate this distribution will be the extensive loss of hard- 
wire communications within the area during the first 72 hours after the earth- 
quake. Marine transport may supplement access to the area, but principal 



IV 



shipment will be by ground and air. Law enforcement in the southern Califor- 
nia area will have to cope with significant variations in the extent of 
damage, and law enforcement procedures should be oriented to regulating 
ground-transportation access into stricken areas and to preventing the 
intrusion of sight-seers, looters, and other undesirables. 

In the northern study area, the San Andreas fault is nearer the urban 
regions and approximately parallels highway corridors that traverse the San 
Francisco peninsula connecting the city to other urban and suburban centers. 
Ground transportation by highway and rail will be severely affected for por- 
tions or all of the 72 hours immediately following the magnitude 8.3 earth- 
quake. Air transportation facilities capable of accommodating large cargo 
planes cannot be counted upon to be in service within the Bay area. The 
closest usable airfields may be Buchanan near Concord and Travis near 
Vacaville. Only helicopter transport can be counted upon to bring medical 
and other needed aid and supplies into the stricken area from the outside. 
This means that a detailed coordination must be made between helicopter land- 
ing sites and modes of distributing the off-loaded material within the 
stricken area. Priorities must be established for the types and amounts of 
material which can be safely delivered from the outside. The feasibility of 
extensive marine transportation should be evaluated as a principal means of 
bringing personnel and materiel into the region. Loss of electrical power, 
water, hard-wire communications, and other support lifelines will greatly 
complicate the emergency-response process and must be provided for in the 
planning. 



Emergency planners should be aware that plans which should be developed 
for the northern and southern scenario earthquakes will necessarily be dis- 
tinctive and will not be interchangeable. For an effective emergency re- 
sponse, it will be necessary for plans to exist that provide for coordination 
between all municipalities and jurisdictions in the affected regions. Since 
some of the lifelines are maintained only by public agencies and others are 
possessions of the private sector, it is mandatory that plans provide for 
emergency responses that integrate the efforts of the public and private 
sectors . 



VI 



CONTENTS 



Page 

PREFATORY COMPARISON OF NORTHERN AND SOUTHERN 

CALIFORNIA EARTHQUAKE PLANNING SCENARIOS iii 

PURPOSE , APPROACH AND DESIGN OF SCENARIO 3 

EXECUTIVE SUMMARY 9 

ACKNOWLEDGMENTS 29 

INTRODUCTION 31 

How to Use the Earthquake Planning Scenario Maps 32 

Limitations of the Earthquake Planning Scenario Maps 34 

SEISMIC INTENSITY DISTRIBUTION 35 

Regional Seismic Intensity Investigations, in General 36 

Development of the Seismic Intensity Distribution Map 

for this Scenario 37 

GENERAL CHARACTER OF THE SEISMIC INTENSITY DISTRIBUTION MAP 45 

EARTHQUAKE PLANNING SCENARIOS FOR LIFELINES IN THE 

SAN FRANCISCO BAY AREA 47 

EARTHQUAKE PLANNING SCENARIO : HIGHWAYS 49 

General Pattern 49 

Description 50 

Planning Ins ights 52 

Recommended Further Work 53 

EARTHQUAKE PLANNING SCENARIO: AIRPORTS 67 

General Pattern 67 

Description 67 

Planning Insights 69 

Recommended Further Work 69 

EARTHQUAKE PLANNING SCENARIO: RAILROADS 75 

General Pattern 75 

Description 75 

Planning Insights 78 

Recommended Further Work 79 



VII 



Page 



EARTHQUAKE PLANNING SCENARIO: MARINE FACILITIES 85 

General Pattern 85 

Description 85 

Planning Insights 88 

Recommended Further Work 89 

EARTHQUAKE PLANNING SCENARIO: COMMUNICATIONS 93 

General Pattern 93 

Description 94 

Telephone Systems 94 

Radio Systems 100 

General Comments on the Communications Scenario 107 

Planning Insights 109 

Recommended Further Work 109 

EARTHQUAKE PLANNING SCENARIO: WATER SUPPLY AND WASTE DISPOSAL Ill 

General Pattern. ...» Ill 

Description 112 

Planning Insights 121 

Recommended Further Work 121 

EARTHQUAKE PLANNING SCENARIO: ELECTRICAL POWER 125 

General Pattern 125 

Description 126 

Planning Insights 132 

Recommended Further Work 133 

EARTHQUAKE PLANNING SCENARIO: NATURAL GAS 137 

General Pattern 137 

Description 137 

Planning Insights 139 

Recommended Further Work 139 

EARTHQUAKE PLANNING SCENARIO: PETROLEUM FUELS 143 

General Pattern 143 

Description 143 

Planning Insights 145 

Recommended Further Work 145 

GLOSSARY 149 

REFERENCES 151 

APPENDIX 155 



vm 



LIST OF 
EARTHQUAKE PLANNING SCENARIO MAPS 



Map No. Subject Located in Text Following Page 

1-S SEISMIC INTENSITY DISTRIBUTION 46 

Lifeline Damage Assessments 

1-HA HIGHWAYS AND AIRPORTS 66 

1-RM RAILROADS AND MARINE FACILITIES 83 

1-C COMMUNICATIONS (Telephone Systems) 110 

1-W WATER SUPPLY AND WASTE DISPOSAL 124 

1-E ELECTRICAL POWER 136 

1-G NATURAL GAS 141 

1-P PETROLEUM FUELS 147 



IX 



EARTHQUAKE PLANNING SCENARIO 

FOR A MAGNITUDE 8.3 EARTHQUAKE ON THE 

SAN ANDREAS FAULT IN THE SAN FRANCISCO BAY AREA 



-2- 



PURPOSE, APPROACH, AND DESIGN 
OF SCENARIO 



Perspective ; Three great earthquakes of magnitude (M) 8+ have occurred in 
California during the state's brief 132-year history, one in Owens Valley 
(1872) and two along the San Andreas fault (1857 and 1906). Since the most 
recent of these great earthquakes early in the century, the state has exper- 
ienced unparalleled growth. As a result, the inevitable, next great earth- 
quake on the San Andreas fault promises to be even more catastrophic than the 
1906 event. Many smaller events continue to cause significant damage and loss 
of life. The 1933 Long Beach and the 1971 San Fernando earthquakes have 
demonstrated the need for improved construction and institutional practices. 
State legislation, changes in local policies, and revisions of the Uniform 
Building Code have since provided for the improvement of these practices. 

The prospect of another great earthquake (M 8.0 or greater) on the north- 
ern San Andreas fault has been a latent source of concern in public policy 
over the years. During the mid-1960s earth scientists began to appreciate the 
dynamics of the earth's crust and to understand the role of the San Andreas 
and other tectonic plate boundary faults in such movement. This insight has 
confirmed the inevitability of future great earthquakes on the San Andreas 
fault. In the mid-1970s, the Palmdale bulge, or southern California uplift, 
drew attention to active deformation of the earth's crust in the vicinity of 
the San Andreas fault. Subsequent analyses of geodetic data relating to the 
uplift and deformation since that time have demonstrated the complexity of 
such phenomena, but do not modify the prospect of a future great earthquake. 



During the late 1970s, K. Sleh explored the history of displacements 
created by large earthquakes on the south-central San Andreas fault by study- 
ing offsets in stratified materials that were exposed in trenches. The 
results of this work have materially advanced the understanding of the fre- 
quency of great earthquakes on the San Andreas fault. A sequence of twelve 
major events has occurred on this segment of the fault over the past 2,000 
years at various intervals ranging between 100 to 200 years, averaging one 
large event about every 140 years. During this decade we will mark the 130th 
anniversary of the 1857 event. In comparison, the chronology of large earth- 
quakes on the northern San Andreas fault, the segment that we are concerned 
with in this scenario, is less certain. However, based on our understanding 
at this time, it is appropriate to consider that another great earthquake can 
occur on the northern San Andreas fault sometime during the next several 
decades and, thus, during the lifetime of many of the residents of the area. 

C hallenge : Following the eruption of Mount St. Helens, the President 
requested the National Security Council to consider the implications of the 
occurrence of a large damaging earthquake in the State of California. The 
results of this analysis were presented in a report published by the Federal 
Emergency Management Agency (FEMA) in January 1981. Several conclusions were 
highlighted. 

o First instance property losses for the M 8.3 event on the northern San 
Andreas fault are estimated to be close to $40 billion. 

o Depending upon the time of day, this M 8.3 event will kill between 3,000 
and 11,000 people and cause between 12,000 and 44,000 people to require 
hospitalization. 



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o A survey of local, State, and Federal government emergency plans has 
Indicated that, although there is a general capacity to respond to small- and 
intermediate-sized earthquakes, it is unlikely that any of these units of 
government can cope with a great earthquake such as a M 8.3 event on the 
northern San Andreas fault. 

Workers in California generally agree with these conclusions. To Calif- 
ornia citizens the message is clear. We must anticipate the occurrence of 
great earthquakes that will overwhelm our present capabilities to respond 
adequately and in an organized manner, both as a society and as individuals. 
Such sobering events satisfy the definition of the term "catastrophic" as it 
is used in this report. The good news is, of course, that appropriate pre- 
earthquake planning and countermeasures can greatly enhance our capability to 
respond to these great events. 

Response : The conclusions of the National Security Council were communi- 
cated to the Governor of California by the President. In response, the 
Governor's Emergency Task Force on Earthquake Preparedness was established in 
February 1981. The Task Force chairman, Dr. William W. Whitson, established a 
group of committees to deal with improvement of emergency-response functions 
such as communications, management of waste and water, search and rescue, fire 
fighting and others. A Threat Assessment Committee was also created to char- 
acterize the outcome of great earthquakes as a basis for improved emergency- 
response planning. The Committee is co-chaired by James F. Davis, the 
California State Geologist, and Karl V. Steinbrugge, structural engineer. 
Members of the Committee include Rachel Gulliver, Mary C. Woods, Janice 
Hutton, Roger W. Sherburne, and Dennis S. Mileti. 



-5- 



Scenarios ; The January 1981 FEMA report has underscored that the occur- 
rence of a great earthquake on the northern San Andreas fault is a matter 
which should engender immediate public concern. The Threat Assessment 
Committee, in conjunction with the chairman of the Task Force, elected to use 
scenarios to serve as a basis for emergency planning. Selected for scenarios 
were a M 8.3 event on the northern segment of the San Andreas fault, similar 
to the event which produced the 1906 San Francisco earthquake, and a M 8.3 
event on the south-central segment of this fault similar to the 1857 earth- 
quake in southern California. 

The general plan of the Committee is to forecast the physical effects of 
the northern and southern California scenario earthquakes. An analysis of the 
ground shaking and ground failure associated with a M 8.3 event on the north- 
ern San Andreas fault is presented in this scenario. This information, 
together with an assessment of the anticipated general damage patterns to 
lifelines, constitutes the Earthquake Planning Scenario map series included in 
this report. 

Earthquake planning scenarios are intended to portray the probable conse- 
quences of catastrophic earthquakes. By this means we communicate the message 
that it is possible to cope with these natural hazards by personal, corporate, 
and government efforts in preparedness planning. Hopefully, this report will 
be constructive to this end. We also intend that it will motivate a commit- 
ment to participation because it provides an understanding that planning and 
action will make a real difference in reducing the dimensions of the disaster. 



-6- 



This planning scenario is intended to contribute to the efforts of the 
following users: 

o Local, State, and Federal officials with emergency planning 
responsibilities. 

o Elected officials who must be able to visualize the threat in order to 
commit themselves to the leadership roles needed to cope with the 
earthquake. 

o Private-sector leaders and planners who must know about and understand 
the hazard in order to prepare for it. 

o Educators, journalists, and other public opinion makers who must appre- 
ciate the threat and communicate its character in order to motivate 
citizen commitment to preparedness. 

o The citizens of northern California who must support public mitigation 
efforts and develop personal strategies for themselves and their 
families in order to minimize the effects of the earthquake on their 
lives. 

It is reassuring that many of these users are participating in the activi- 
ties of the Governor's Emergency Task Force on Earthquake Preparedness, which 
during 1981 and 1982 has numbered between 300 and 400 individuals. 



■7- 



-8- 



EXECUTIVE SUMMARY 



This scenario portrays anticipated damage to the highway, airport, rail- 
way, marine, communication, water, waste disposal, electrical power, natural 
gas, and petroleum lifelines that service the metropolitan areas of the great- 
er San Francisco Bay area, when this area is subjected to a large (magnitude 
8 +) earthquake, an event expected to take place during the lifetime of many 
of the current residents. The principal challenge in responding to the conse- 
quences of this event will be the transport of people and materiel within as 
well as from outside the stricken region. Emergency preparations should be 
based upon the assumption that electrical power, communications, water sup- 
plies, and sewage treatment facilities will be significantly affected. 

Most of the lifelines will experience significant adverse effects, and 
coping with any one of them would require a major emergency-response effort. 
The combined impact of all the lifelines being simultaneously impaired by the 
scenario earthquake greatly escalates the problem. The added strain of deal- 
ing with the thousands of deaths and casualties requiring hospitalization that 
will result from this earthquake will put an unprecedented demand upon govern- 
ment institutions, utilities, businesses, individuals, and society in general. 
The circumstances will be catastrophic, i.e., they will overwhelm our institu- 
tional and personal capacities to cope, unless public awareness and emergency 
preparedness can provide an adequate means of responding. The information 
presented in this report is intended to be a basis for such planning and 
preparedness. 



-9- 



In developing this earthquake planning scenario, the California Division 
of Mines and Geology (CDMG) assumed the occurrence of a M 8.3 event on the 
northern segment of the San Andreas fault, similar to the event that produced 
the April 18, 1906 San Francisco earthquake. A regional intensity map to be 
employed in the assessment of lifeline damages was prepared using the Evernden 
computer model (Evernden and others, 1973, 1981) for calculating seismic 
intensity and based in part on an intensity map published by the U.S. Geologi- 
cal Survey (1981) for the M 8.3 event on the northern San Andreas fault that 
is addressed in this scenario. CDMG modified this intensity map to reflect 
more detailed and additional geological information that was not included in 
Evernden' s analysis. On the basis of its inclusion of information on local 
geology and ground water conditions, CDMG also delineated areas of potential 
ground failure. Thus, CDMG's SEISMIC INTENSITY DISTRIBUTION map (Map 1-S) 
shows anticipated intensities for both shaking and ground failure. 

Intensity zones are shown on the map as isoseismal areas — that is, as 
areas within which the anticipated seismic intensities, or local earthquake 
effects, are considered comparable. Each intensity zone is assigned an inten- 
sity rating based on the Rossi-Forel (R-F) intensity scale (see Appendix). 

The areas of predicted intensity 9 (R-F) include most of the low-lying 
lands surrounding San Francisco and San Pablo Bays. This area of intense 
shaking encompasses a major portion of the more highly developed urban areas 
including most of the Santa Clara Valley and portions of San Francisco, 
Oakland, and virtually all of the other communities that border the Bays. In 
addition, portions of this area that are situated on Bay mud are susceptible 
to ground failures. This additional hazard is present in parts of Oakland, 



-10- 



Alameda, Richmond, San Jose, and San Francisco, and to some extent it affects 
all the communities located adjacent the Bays. Intensity 9 (R-F) shaking is 
also forecast for the Santa Rosa-Sebastopol area. 

Intensity 8 (R-F) shaking is predicted for those portions of the East San 
Francisco Bay communities where, in general, the water table is at a depth of 
more than 10 meters from the surface, in the Diablo and Livermore Valleys, 
parts of the North Bay and, primarily because of their proximity to the fault, 
most of the San Francisco and Marin peninsulas. 

Most of the remainder of the planning area, generally the more mountainous 
and less-populated areas east of the Bay, have a predicted intensity of 
7 (R-F) or less. 

These regional patterns of seismic intensity distribution associated with 
this scenario event are of sufficient plausibility to form a credible basis 
for evaluation of general effects upon lifelines that service the greater San 
Francisco Bay area. The following discussions highlight the anticipated 
regional consequences on these lifelines. 



Highways 

Map 1-HA displays the regional effects of the scenario earthquake upon the 
highway system. Damage to highways will have its greatest impact on the San 
Francisco Peninsula, where vehicular traffic into and out of the City of San 
Francisco and much of San Mateo County may be impossible for many hours until 



-11- 



one or more corridors become available. Use of the Golden Gate, San Fran- 
cisco-Oakland Bay, Richmond-San Rafael, and San Mateo bridges will be 
impossible for an extended period. All peninsula routes west of the San 
Andreas Fault will be closed. Some major arteries in Santa Clara County will 
be heavily damaged, but the many available routes will permit rapid restora- 
tion of reasonable traffic flow. In the East Bay, routes closest to the Bay 
margin will be most seriously damaged, notably Route 17 between Richmond and 
San Leandro. Other major arteries closer to the Oakland Hills will be avail- 
able, however, subject to occasional detours. Major routes into the damaged 
areas from the east will be available, including Interstates 80 and 580 with 
connections to Interstate 680 and Route 24. In the North Bay, the major 
problems will be along U.S. 101 in the Santa Rosa area and in southern Marin 
County, where access to and from the area south of San Rafael will be severely 
limited. Experience has indicated, however, that alternative routes can 
generally be rapidly developed. While lengthy delays and detours will be 
common, most of the initial confusion will be under control within a few days. 

Planning insights : Emergency planners need to identify major emergency 
corridors that can be most readily opened immediately following the earth- 
quake. In contrast to some segments of the freeway system that are above or 
below grade, with many structures subject to damage, alternative emergency 
routes should be selected which are at grade, wide, not likely to be signifi- 
cantly affected by fallen powerlines or other obstructions, and not flanked by 
buildings likely to be heavily damaged. Selection of emergency corridors is 
especially important in the urban areas of San Francisco, San Mateo, and Santa 
Clara counties, and in Oakland, Berkeley, and Alameda in the East Bay, where 
significant damage is expected. Wherever possible, alternate corridors should 
be established so that flexibility is achieved. 



-12- 



The utilities and local government agencies should identify all such 
installations and facilities that they will need to inspect, repair, operate, 
or otherwise have access to in this emergency. 

Emergency planners need to examine available routes to critical facili- 
ties, assess the potential for damage, and identify the most probable access 
routes. Critical facilities include communica- tion centers, hospitals, 
airports, heliports, staging areas, fuel storage sites, and other locations 
essential to emergency response. 

Access to the area with supplies and personnel from cities in the Great 
Valley and southern California will be available. Highway emergency response 
plans should be coordinated with air, rail, and marine transport scenarios in 
order to optimize plans for integrated transportation capability. Access to 
the stricken area and travel within it will be difficult and will be limited 
to the highest emergency priorities. 

Recommended further work : Assessment of highway performance and identifi- 
cation of alternative emergency routes is especially important in all areas 
where major damage is a reasonable expectation. 



Airports 

Emergency air transport into the stricken region from the outside is vital 
to response activities during the first 72 hours following the earthquake. 
Consideration of expectable damage to major airport facilities (see Map 1-HA) , 



-13- 



notably the runways and land access routes, leads to the conclusion that the 
San Francisco International and Metropolitan Oakland International airports, 
as well as Alameda Naval Air Station and Hamilton Field, will be unavailable 
for major airborne relief operations (C-141 aircraft and massive logistics). 
San Jose Municipal, Hayward Municipal, and Buchanan Field will be available 
with limitations. Thus, delivery of massive emergency aid from outside the 
area will be hampered by the lack of a close-in major facility. Travis Air 
Force Base near Fairfield becomes the logical choice for large-scale emergency 
operations. 

Planning insights : Airborne transport will play a vital role in the 
transport of people and materiel to and from the stricken areas and in search 
and rescue, damage assessment, and many other emergency response efforts. 
Pre-selection of one or more air cargo delivery facilities will influence 
planning for distribution of material by helicopter, highway, rail, and marine 
transport. Integrating these various delivery systems to accomplish this mis- 
sion will be challenging. Use of helicopters within the heavily damaged areas 
is seen as an extremely important function requiring appropriate planning. 

Recommended further work : Secondary airports for distribution of supplies 
and equipment need to be evaluated in terms of the availability of auxiliary 
electrical power, the integrity of airport buildings, and the vulnerability of 
surface access ground routes in order to finalize transportation plans. The 
vulnerability of runways at San Jose Municipal Airport, in particular, needs 
to be evaluated further, since more data can either confirm or modify the 
conclu- sions presented in this report. Facilities suitable for helicopter 
operations within the stricken area should be selected, particularly in San 
Francisco, San Mateo, and southern Marin County. 



-14- 



Railroads 

Rail facilities along each of the principal rail corridors leading to the 
San Francisco Bay Area are subject to major damage and resulting route closure 
(see Map 1-RM) . Therefore, for planning purposes, rail transport to and from 
the Bay area is assumed to be unavailable for at least the initial 72-hour 
period following the earthquake. Rail facilities serving the urban areas 
around the Bay are also highly exposed to damage; while some segments of these 
lines could be operational, their probable utility would be minimal. Facili- 
ties of the Bay Area Rapid Transit System (BART) will be damaged or will 
require safety inspections to an extent that will render the system totally 
inoperative during the initial 72-hour post-earthquake period. 

Planning insights : Rail facilities within the urban areas surrounding the 
Bay will be non-operational. Accordingly, if rail transport is essential to 
recovery efforts, consideration must be given to selection of appropriate rail 
terminals where material can be off-loaded for truck, airborne, or barge 
transport. Railheads at Benicia and Vallejo may be most critical for movement 
of heavy equipment by barge to heavily damaged areas in Marin County and the 
San Francisco peninsula. Integrated planning needs to be undertaken for air, 
rail, highway and marine transports. 

Recommended further work : Consideration should be given to the possibil- 
ity of establishing temporary terminals following the earthquake where ser- 
viceable tracks come into the Concord and Livermore Valley areas for off-load- 
ing of major supplies and equipment. Railheads at Benicia and Vallejo should 
be examined to determine their adequacy for transport of heavy equipment from 
rail to barge. 



-15- 



The relative vulnerabilities of the routes that give access to the Bay 
area via northern Contra Costa County also need to be evaluated. -A detailed 
engineering and geologic examination of these routes may reveal that rail 
transport to a closer-in staging area near Richmond (that might also permit 
transfer of materials to barges) is a viable possibility. 



Marine Facilities 

Map 1-RM depicts the earthquake planning scenario for marine facilities in 
the area. The majority of the docks around the Bay are pile supported and 
these should not be significantly damaged. Operations at the container termi- 
nals, however, which are generally constructed on fill, will be seriously 
impaired. Disruption of rail facilities, impaired highway access, toppling of 
cranes, pipeline ruptures, and similar problems will be controlling factors 
affecting the use of the various port facilities. 

The use of barges to transport heavy equipment and supplies to heavily 
damaged areas will be dependent on the integrity of docks. The major Bayside 
facilities at San Francisco, Oakland, Richardson Bay, Richmond, and the 
Carquinez Straits should be accessible for tug and barge operations. South of 
Hunters Point and San Leandro all facilities would be inaccessible to larger 
vessels including tug and barge traffic. 

Planning insights : The use of tugs and barges to transport heavy equip- 
ment and supplies to the San Francisco and Marin peninsulas appears to be a 
viable emergency-response procedure. Assuming that most of the docks in the 



-16- 



heavily damaged areas will be usable, availability of emergency power and 
off-loading capabilities will be requisite. Use of barge transport will nec- 
essitate coordinated planning for loading of needed material at a dockside 
facility adjacent to a marshalling depot and/or railhead with corresponding 
loading capabilities. 

Transport of emergency personnel and equipment into these same heavily 
damaged areas and evacuation of the injured will be a vital function of the 
numerous Bay ferries. Planning should consider the most feasible terminals 
(on both ends) in order to complete these missions. Again, coordination with 
the various ground transport capabilities will be required in order to effect 
efficient transfers. 

The utilization of privately owned vessels to augment this supply and 
evacuation effort is appropriate. Practical education, planning, and training 
programs to implement this participation should be initiated. 

Recommended further work : The various roles that marine transport can 
assume in the emergency response efforts and the extent of marine transport 
resources should be determined. The port facilities in the areas of expected 
heavy casualties/damage should be assessed, and locations that have suitable 
land-access and loading capabilities and that are most likely to be available 
for post-earthquake access to marine transport should be selected. Port 
facilities outside the heavily damaged areas should be coordinated with ground 
transport to identify the most efficient means of transporting the injured, 
materiel, etc. 



-17- 



The capabilities of private vessels and the potential roles of their oper- 
ators should be determined. Appropriate training programs should be estab- 
lished to ensure the emergency-response effectiveness of this resource. 



Communications 

Telephone communications (see Map 1-C) will be adversely affected due to 
well-known overloading effects resulting from post-earthquake calls within the 
area and from the outside. This situation will be further complicated by loss 
of service due to physical damage to equipment from ground shaking and loss of 
electrical power and subsequent failure of some auxiliary power sources. 
Moreover, not all of the systems in the region are set up to process emergency 
calls automatically on previously established priority bases. Thus, overload- 
ing of equipment still in service could be very significant. 

This post-earthquake communications scenario is primarily an estimate of 
how much the effectiveness of telecommunications systems will be reduced by 
the earthquake. "Effectiveness" is defined as the ability of a system to 
perform to its design limits and provide the intended service following the 
earthquake. The effectiveness scale is applied to a three-day time frame. 
Four levels of effectiveness over time were distinguished and used as the 
basis for zoning the study area (Zones A, B, C, and D) . Zone D areas will 
have the greatest loss of effectiveness over the three-day period, Zone A 
areas the least. 



-18- 



There is a very good system in San Francisco for identifying important 
public safety telephone circuits. These dedicated lines should be minimally 
disrupted. San Francisco is assigned the lowest effectiveness rating (Zone 
D) , however, because (1) the telephone system in the city is expected to have 
systemic failures not readily compensated by alternative traffic routing and 
(2) a high percentage of the company employees who will be needed for the re- 
covery effort live outside the city limits and important transportation routes 
will be impassable. The volume of telephone calls following the earthquake, 
if it occurred after normal business hours, would not be as heavy and paralyz- 
ing to the telephone system in San Francisco, with its high business concen- 
tration, as it would be during that time period in more heavily residential 
areas. But, although the system in San Francisco has line access control, it 
is more isolated systematically than the Los Angeles metropolitan area, for 
example, and is very dependent upon a few telecommunications arteries. 

In Marin County, telephone system vulnerability was evidenced by the 
January 1982 storms. The geography and demography is such that alternate 
routing is limited. Key central offices are located in areas expected to 
suffer severe shaking and ground failure. Many access routes will be impass- 
able. This area is particularly susceptible to underground cable and surface 
cable carrier failure. Line load control is available but would not alleviate 
other systemic problems. 

Although the Oakland/East Bay area has a substantial number of telephone 
facilities located in areas of intense shaking and high probability of ground 
failure, access to accomplish repairs should not be a major problem. Further, 
there are several switching options. Systems in this region have line access 
control and predesignated public safety circuits. 



-19- 



Systems in the San Jose/South Bay area will experience severe shaking in- 
tensities and have extensive areas of potential ground failure. Despite this, 
repair staff should be in reasonable proximity to their offices and have fewer 
access problems than adjacent areas. The telephone systems will be saturated, 
but they have designated circuits and line load controls. Because of shaking 
patterns corresponding with key facility locations, the South Bay area is 
likely to experience complete localized telephone failures on a block-by-block 
basis. 

Radio systems will generally operate at 40% effectiveness for the first 
12 hours after the earthquake, increase to 50% for the second 12 hours, then 
begin a slow decline to approximately 40% within 36 hours. The long-term im- 
plications are that individual systems gradually will become less useful to 
the overall recovery effort when supplanted by systems relocated from outside 
the disaster area. It is unlikely that public safety radio systems would 
become saturated with non-critical communications from mobile units; it is 
clear, however, that radio traffic densities on redundant (non-emergency- 
designated) channels would increase, particularly when remote base station and 
repeater failures would tend to limit the number of redundant channels avail- 
able. Nonetheless, after 12 hours, at which time the number of operable units 
will have declined (with exhaustion of emergency power fuel) and recovery 
efforts will have restored some order, the radio traffic density problem will 
ease. 

Emergency power has been the primary cause of communications failure in 
past disasters. Poor installation practices and inadequate preventative main- 
tenance of backup power equipment contribute to a high failure rate of radio 



-20- 



systems. The presumed scarcity of propane and gasoline after a major earth- 
quake will strictly limit the viability of surviving communications sites. 

The availability of repair parts and the ability to transport them are 
other factors that should be considered when planning for effective short- and 
long-range emergency responses. We believe that supplanted communications 
systems will be needed as local systems suffer earthquake-caused (and normal) 
equipment malfunctions for which there are no repair parts. 

Planning insights : A general communication plan should be developed for 
use following the earthquake by appropriate agencies and personnel with emer- 
gency response roles. This plan should anticipate the needs of the most vital 
parties. Reliance on emergency telephone communications should be kept at a 
minimum. A strategy should be developed for communication to the general 
public which relies upon the capabilities of surviving commercial radio and 
television stations. 

Recommended further work : An inventory of commercial and amateur broad- 
casting capabilities should be undertaken and the resulting information 
employed in developing the regional emergency communications plan. A survey 
of existing critical communications facilities should be undertaken by struc- 
tural engineers leading to development of improved equipment installation 
standards. There is need for a technical examination of alternative means of 
communication, e.g., satellite. 



-21- 



Water Supply and Waste Disposal 

Several of the major aqueducts that deliver imported water to various seg- 
ments of the planning area will sustain damage causing temporary interruptions 
in supply (Map 1-W) . The numerous major reservoirs in the area provide ample 
storage to meet demands during the time required for repairs. However, 
impairments to water transmission lines, local storage reservoirs, and pumping 
plants, as well as the local distribution systems will affect water availabil- 
ity and pressure. The absence of electrical power for extended periods will 
in some areas preclude water deliveries where pumping is necessary, even 
though conveyance facilities may be intact. Many areas will be dependent on 
tanker trucks to provide their basic needs. For planning purposes, one major 
dam (Lower Crystal Springs Dam in San Mateo County) is assumed to incur major 
damage necessitating downstream evacuation procedures. 

Sewage collection systems (Map 1-W) will sustain widespread damage, parti- 
cularly in the low-lying areas nearer the Bay. The many sewage treatment 
facilities, most of which are located in structurally poor ground adjacent to 
the Bay, will suffer damage resulting in discharge of raw sewage into the Bay. 

Planning insights ; The various water agencies need to develop and conti- 
nue public education programs to acquaint their water users with the prospects 
of contamination and loss of water supply and how to mitigate these potential 
problems. 

Plans for firefighting need to be coordinated with water agencies and 
alternative sources of water planned for in critical areas. 



•22- 



Additional interconnections between the major water delivery systems 
should be considered to provide valuable flexibility in water operations, 
e.g., connections between the Hetch Hetchy Aqueduct and facilities of the East 
Bay Municipal Utility District and between the Hetch Hetchy Aqueduct and 
facilities of the Santa Clara Valley Water District. 

Recommended further work ; Water agencies need to examine their transmis- 
sion and distribution systems in detail to identify areas and facilities most 
likely to be impaired. Ongoing programs should be maintained to progressively 
upgrade facilities of questionable seismic resistance in areas of high 
vulnerability. 

Capabilities to provide emergency distribution of water using ground 
transportation need to be evaluated in areas which are identified as having 
significant possibility of impaired water availability. 

Feasibility of providing additional interconnections between various 
transmission systems should be considered in order to provide alternative 
supply routes. 

There is a need to determine the effects of a prolonged lack of electrical 
power for pumping water to various portions of the Marin and San Francisco 
peninsulas. 

Fire fighting water requirements should be assessed in critical areas, and 
estimates should be made of the expected water supply impairment. 



-23- 



Electrical Power 

The occurrence of a great earthquake near this major urban area will have 
a very significant impact on the many facilities that comprise this complex 
electrical power network. (See Map 1-E.) Damage to power plants and their 
ancillary facilities within the planning area and in adjacent areas affected 
by the earthquake can be expected to result in a reduction in combined gener- 
ating capacity of up to 50 per cent. The impact of this reduction in output 
is not expected to be great, however, because power is available from other 
sources outside the planning area and because of the significant reduction in 
demand. Immediate concerns will involve repairs necessary to restore power 
within the damaged areas of greatest need. Major restoration problems will 
involve repairs necessary to route power through the major substations, repair 
of damaged and collapsed transmission-line towers, restoration of equipment at 
local substations, replacement of fallen poles and transformers, etc. 

It is a reasonable expectation that virtually all of the planning area 
will be without power, at least temporarily, during some portion of the first 
72-hour period. Algermissen and others (1972) estimated that "It is reason- 
able for planning purposes to consider 50 per cent of the service connections 
in the study area to be without power for 24 hours after a magnitude 
8.3 shock.... in the congested portions of San Francisco and Oakland, the power 
outage should be considered at 100 percent for 24 hours, and thereafter at 
75 percent for an additional 24 hours." 

Electrical power facilities on the Marin and San Francisco peninsulas are 
particularly vulnerable to damage and restoration of power under the best of 



-24- 



conditions could be prolonged. While the resources may be available to exped- 
itiously deal with repairs to the system, the many complicating factors 
involved in attempting to conduct an extensive repair operation amidst the 
confusion and destruction that will exist will be a challenge. Realistically, 
power is unlikely to be restored to many areas for extended periods of time. 
Planning that involves power dependent systems should take into consideration 
this possible eventuality. 

Planning insights: Society has evolved to where it is highly dependent 
upon a continuous supply of electrical power to meet a myriad of everyday 
needs. Consequently, everyone, and particularly those entities responsible 
for maintenance of lifelines and critical facilities should examine their 
ability to function in the event of a prolonged absence of electrical power. 

At the individual level, the following is very appropriate. Commenting 
upon the lack of electrical power in Santa Cruz County that resulted from the 
intense storm during the week of January 4, 1982, Stegner (1982) concluded: 
"It may be a long time before we need to dig out our old boy scout manuals 
again, but, while we sit around waiting for the killer earthquake that every- 
body seems to regard as inevitable , we might take a lesson from the killer 
storm that nobody expected. The differnce between misery and comfort, rela- 
tively speaking, may be no more than a can of kerosene and a can of gasoline 
in the garage, a can of soup in the larder, and a half dozen flashlight 
batteries in the kitchen drawer. What was the motto? Be prepared?" 

IT IS ASSUMED THAT ALL CRITICAL FACILITIES SUCH AS HOSPITALS, FIRE AND 
POLICE STATIONS, EMERGENCY COMMUNICATIONS AND OPERATION CENTERS, AND WATER 



-25- 



PUMPING STATIONS WILL REQUIRE STANDBY GENERATING EQUIPMENT AND EMERGENCY FUEL 
SUPPLIES IN SAN FRANCISCO, SAN MATEO, SANTA CLARA, AND MARIN COUNTIES. 

Recommended further work : The critical power corridors and facilities 
should be examined in light of the best geologic data available to assess the 
vulnerability of various elements in the electrical power network. Capability 
to respond and accomplish timely repairs to a widespread affected area as 
described in this scenario should be thoroughly evaluated. Probable interrup- 
tions of other lifelines that are discussed in this report should be taken 
into account in planning an earthquake-emergency response for this utility. 



Natural Gas 

Damage to natural gas facilities (Map 1-G) will consist primarily of (a) 
some isolated breaks in the major transmission lines and (b) innumerable 
breaks in mains and individual service connections within the distribution 
systems, particularly in the areas of intense shaking and/or structurally poor 
ground nearer the Bay margins. For planning purposes, it should be considered 
that these many leaks in the distribution system will affect a major portion 
of the urban areas in the East Bay, South Bay, and the San Francisco and Marin 
peninsulas resulting in a loss of service for extended periods. Sporadically 
distributed fires should be expected at the sites of a small percentage of 
ruptures both in the transmission lines and in the distribution systems. 

Transmission pipelines serving the San Francisco Peninsula are most vul- 
nerable to damage. Damage and repair problems to major transmission lines in 



-26- 



the East Bay should not be significant. No significant damage to transmission 
facilities in the North Bay is envisioned. 

Planning insights : The various major utilities should collaborate in con- 
tinuing public education programs to explain the probable consequences of a 
major earthquake on their service capabilities and what actions can be taken 
to mitigate the effects. 

Recommended further work : In areas of structurally poor ground where the 
potential for major pipeline failure exists, alternative line(s) in stable 
materials should be considered. The adequacy and location of automatic 
pressure-activiated shut-off valves should be periodically reviewed in the 
light of new geologic information concerning potential problem areas. 

Locations where gas availability would be most severely impacted should be 
identified. Emergency users of natural gas should be identified. The likeli- 
hood of fire due to breaks in local gas mains should also be investigated. 



Petroleum Fuels 

Following the scenario earthquake, operations at the several major refin- 
eries in the Bay Area will be curtailed until all facilities are thoroughly 
inspected and repairs accomplished (see Map 1-P). Pipelines are expected to 
withstand the shaking fairly well, but ruptures can be expected wherever con- 
trasting ground conditions produce differential movements and wherever ground 
failure occurs due to liquefaction or seismically-triggered landslides. Large 



-27- 



storage tanks and marine loading facilities located on questionable foundation 
materials are also subject to damage. 

Planning insights ; Plans should be developed to ensure distribution of 
fuel to those locations designated for emergency response operations, includ- 
ing airports. Appropriate facilities, including emergency power and pumping 
capability, should be available at fuel storage locations for refueling of 
helicopters and other emergency vehicles. Major damage to the trans-Bay 
product lines could seriously impact fuel availability on the San Francisco 
peninsula. 

Recommended further work: All petroleum product pipelines serving the 
metropolitan areas should be examined in detail relative to their exposure to 
ground failure. The adequacy and locations of automatic shut-off valves 
should be examined on all product lines and remedial measures undertaken to 
ensure a functional system. Locations of fuel storage facilities, including 
those for aviation fuels, should be predetermined and emergency procedures 
established to ensure that these supplies will be available when needed. An 
inventory of fuel storage facilities throughout the area would facilitate 
planning of emergency response efforts that will be dependent upon nearby 
sources of fuel. 



-28- 



ACKNOWLEDGMENTS 

This Earthquake Planning Scenario represents input from many sources — 
notably, the major public utilities and various smaller utility districts, 
Federal, State and local government agencies, members of the Advisory Commit- 
tees of the Governor's Task Force, and the staff of the California Division of 
Mines and Geology. In addition, many organizations and individuals, requested 
to comment on various aspects of the work while in progress, provided thought- 
ful comments on specific items. We particularly want to acknowledge the co- 
operation and assistance of the major utilities, who were extremely helpful in 
the compilation of the lifeline inventories and in discussions of the earth- 
quake resistance of various critical facilities. To all who participated in 
this effort, we express our sincere appreciation. 

We are especially indebted to Dr. Karl V. Steinbrugge (Co-Chairman of the 
Threat Assessment Committee of the Governor's Task Force), who collaborated 
with us in many areas and who provided guidance and valuable counsel through- 
out the course of this study. 

We are appreciative of Ms. Jan Denton, Director of the Department of 
Conservation, who has supported this investigation throughout; Dr. Jack F. 
Evernden, who developed the seismic intensity model and who, with Drs. Roger 
Borcherdt and Robert D. Nason (all of the U.S. Geological Survey), offered 
valuable perspectives on the vagaries of forecasting intensity distribution; 
engineers James A. Gates and Oris H. Degenkolb, who with geologic input from 
Marvin L. McCauley (all of the California Department of Transportation) pro- 
vided much of the data for the highways scenario. Recognition must also go to 
Alex R. Cunningham, Director of the State Office of Emergency Services (OES) , 



-29- 



Jack J. Kearns, Deputy Director of OES, and Jane V. Hindmarsh, Special Assis- 
tant to the Governor's Emergency Task Force on Earthquake Preparedness; to Dr. 
William W. Whitson, Chairman of the Governor's Task Force, who provided both 
inspiration and advice; to Ms. Jeanne Perkins of the Association of Bay Area 
Governments (ABAG) , O.W. Steinhardt and George F. Gaebler of the Pacific Gas 
and Electric Company, Harry W. Tracy and Jack M. Barron of the City of San 
Francisco; and to members of various advisory committees of the Governor's 
Task Force including B. B. Blevins of the California Energy Commission, John 
E. Brown of John E. Brown and Associates, Inc., Consulting Structural Engi- 
neers, Robert L. Cheney of the Pacific Telephone and Telegraph, James G. 
Cotter and Mason D. Riegel of the California Department of General Services, 
Donald J. Finlayson of the California Department of Water Resources, John E. 
Hampton of Marlex Oil and Refining, Inc., Gordon L. Laverty of the East Bay 
Municipal Utility District, and Michael M. Murphy of Pacific Merchant Shipping 
Association. 

Thanks are also due to Threat Assessment Committee members Rachel 
Gulliver, Janice Hutton, Roger W. Sherburne, and Dennis S. Mileti. 

Within CDMG we wish to accord special thanks to Mary C. Woods, editor of 
CALIFORNIA GEOLOGY, who has served with James F. Davis, State Geologist, as a 
member of the Threat Assessment Committee (her help has been indispensible) . 
We are also indebted to Millie E. Anderson, Carole R. Johnson, Yolanda Silva, 
Darren White, Patty Gouvea, and Cheryl Zeh for typing the manuscript. Merl 
Saith has supervised drafting efforts and overseen publication. Jeff Tambert, 
head of the drafting group, did an outstanding job in managing the compilation 
of the many maps and coordinating the efforts of Ed Foster, Louise Huckaby, 
Frances Rubish, and Anna Stratton. 



-30- 



INTRODUCTION 



On April 18, 1906, most of northern and central California was shaken by 
one of the three great (Magnitude 8 +) earthquakes that have struck the State 
during the past 125 years. Communities throughout the greater San Francisco 
Bay region were heavily damaged and the resulting fire destroyed much of the 
City of San Francisco. During the past three-quarters of a century this re- 
gion, lying alongside the great San Andreas fault, has experienced tremendous 
growth, evolving into a vast urban complex of several million people. 

Sometime during the remaining years of this century or early in the next, 
the San Francisco area will in all probability again be affected by a great 
earthquake along the northern segment of the San Andreas fault. An earthquake 
similar to the 1906 event will have a magnitude of approximately 8 on the 
Richter scale, and, in addition to its direct impact on a vastly increased 
population, it will test the many and varied cultural works that have been 
developed during the interim. Some older facilities will be seriously damaged 
or destroyed since they were not built to withstand intense shaking and may be 
situated upon ground that will fail. 

This report and accompanying EARTHQUAKE PLANNING SCENARIO maps extend the 
work begun by Algermissen and others (1972). In addition to predicting the 
extent of damage likely to occur to lifeline facilities, this scenario endeav- 
ors to specify where damage will occur. Because this scenario is based upon 
the occurrence of a specific earthquake on the San Andreas fault, it is not 
valid for the assessment of possible damage produced by an earthquake on any 
other fault or by a different earthquake on the San Andreas fault. 



-31- 



The EARTHQUAKE PLANNING SCENARIO maps included in this report reflect the 
fact that earthquake damage will not be uniform. Damage will be related to 
the design of specific structures, the geologic ground conditions upon which 
they are built, their distance from the fault, and the character of the earth- 
quake generated wave forms to which they are subjected. Many structures have 
been designed to resist earthquake shaking, while others have not. 

The ground surface in areas of competent bedrock is not likely to suffer 
permanent deformation (ground failure). On the other hand, structures on com- 
pressible deposits, particularly where the water table is high, are subjected 
not only to the effects of relatively low frequency, high amplitude vibra- 
tions, but possibly also to disruption caused by differential settlement, 
lateral displacement, or liquefaction. 

In general, earthquake effects diminish with distance from the causative 
fault. These considerations are reflected in the damage assessments described 
in this report. 



How to Use the Earthquake Planning Scenario Maps 

For emergency planning purposes, it is important to have an assessment of 
the effects of the scenario earthquake upon principal lifelines. The present 
investigation provides a regional characterization of anticipated damage pat- 
terns. CDMG's approach in formulating this assessment was, first, to inter- 
pret the regional pattern of ground shaking and ground failure and, second, to 
evaluate the resulting performance of lifeline segments throughout the area. 



■32- 



In this way, CDMG reached conclusions which constitute the regional post- 
earthquake damage pattern for each of the lifelines. It was not feasible to 
rigorously determine the effects of the scenario earthquake on each individual 
bridge, overpass, or other lifeline structure. To accomplish such exhaustive 
analyses would require subsurface sampling of soil and rock at each site in 
order to assess potential ground shaking and ground failure. Moreover, an 
engineering analysis of the manner in which specific structures would respond 
to the anticipated types of ground shaking would be necessary to draw more 
definitive conclusions. It is, therefore, improper to use the earthquake 
scenario conclusions to forecast the effects of the scenario earthquake for 
any other purpose than emergency planning. For example, decisions on whether 
or not to replace or retrofit certain lifeline components should definitely be 
based upon more intensive and rigorous investigations than were practicable 
for this project. 

In general, people in well-designed structures built upon firm bedrock 
some distance from the fault will be able to aid people in poorly-designed 
structures built upon soft alluvium near the fault. While no scenario will 
prove accurate in detail, a general effort such as this provides planners with 
a regional pattern of the magnitude and types of problems that will confront 
emergency-response personnel. As more detailed engineering and geologic data 
become available, these maps will be periodically updated. Other scenarios, 
could be developed for earthquakes on other faults, or for different earth- 
quakes on the San Andreas fault. Once these scenarios are developed a more 
complete understanding of the earthquake hazard within the planning area will 
be possible. 



-33- 



Limitations Of The Earthquake Planning Scenario Maps 

A description of the regional impacts of the scenario earthquake is pre- 
sented for each lifeline, together with a discussion of the planning insights 
which are implied by the damage patterns. Where appropriate, further work is 
recommended. Next, an annotated list of damage assessments for each lifeline 
precedes the planning scenario maps which portray the geographic location of 
earthquake effects. 

1. The maps in this report illustrate only a regional pattern of damage, 
specifically, one that it is plausible to expect from a great earthquake 
(magnitude 8.3) on the northern San Andreas fault. The maps do not pre- 
sent assessments of the damage produced by shaking from earthquakes which 
may take place on other faults or on other segments of the San Andreas 
fault. 

2. The seismic intensity forecasts upon which the damage distribution is 
dependent are interpretative. There are various judgments among workers 
regarding which is the most appropriate model for forecasting intensity. 

3. The quality of information upon which the ground-failure forecasts have 
been made varies from area to area within the study region. Only general 
geologic information is available concerning ground conditions associated 
with most lifeline elements. Modeling of ground shaking on a regional 
basis using this generalized geologic information can produce plausible 
damage conclusions which are appropriate for emergency planning. Other 
types of conclusions regarding specific structures, such as the desirabil- 
ity of upgrading seismic resistance, etc., require more detailed geologic 
information and more extensive engineering analysis than was practical for 
this study. 



-34- 



SEISMIC INTENSITY DISTRIBUTION 
FOR A M 8.3 EARTHQUAKE ON THE SAN ANDREAS FAULT 

(Map 1-S) 



To develop an earthquake planning scenario, it is necessary first to esti- 
mate the regional patterns of ground shaking and ground failure. This proce- 
dure is aided by assuming that the effects of the scenario earthquake will be 
interpretable from previous earthquakes about which there is some knowledge. 
In this instance the scenario earthquake has been assumed to be similar to the 
great San Francisco earthquake of April 18, 1906. The effects of that earth- 
quake are well documented in the literature, including the classic "Report of 
the State Earthquake Commission" (Lawson and others, 1908). These observed 
effects provide a means of confirming the general validity of the regional 
seismic intensity map developed for assessment of modern lifelines in the San 
Francisco Bay area. 

"Seismic intensity" is the local effect of an earthquake at a particular 
point of reference (Barosh, 1969, p. 6). Unfortunately, forecasting seismic 
intensity has inherent problems. This is primarily because intensity scaling 
is based upon generalizations. With a single numerical value, scaling 
attempts to convey all of the various effects of earthquake shaking upon 
humans and their cultural paraphernalia. The measurement of seismic inten- 
sity, therefore, is unavoidably subjective. Over 44 different intensity 
scales have appeared during the last century (Barosh, 1969, p. 6). 



-35- 



Regional Seismic Intensity Investigations, In General 



Forecasting seismic intensity patterns resulting from a specific earth- 
quake is complicated by other considerations in addition to uncertainities in 
describing and scaling earthquake effects. Assessing the intensity distribu- 
tion of an anticipated scenario earthquake requires the investigator to deter- 
mine approximate ground shaking and ground failure conditions at reference 
points throughout the area. To scale the intensity of these physical para- 
meters, it is necessary to interpret their consequences upon a variety of 
types of construction at the reference points. 

The degree of ground shaking at a specified location resulting from the 
scenario earthquake is dependent upon a number of considerations. Among the 
most influential is the distance from the causative fault. Generally, the 
amplitude of vibratory motion diminishes away from the source of excitation 
through the process of attenuation. The vibrations associated with earth- 
quakes are complex. Characterizing their anticipated effects on ground shak- 
ing at specific reference points is further complicated by the different geo- 
logic materials through which they pass. Well-consolidated bedrock, for 
example, transmits most frequencies while unconsolidated sand and gravel or 
water-saturated mud preferentially transmit low frequencies. 

Development of seismic intensity maps also requires consideration of the 
consequences of ground failure. In contrast to vibratory shaking, ground 
failure is a permanent displacement of earth materials resulting from such 



-36- 



secondary earthquake- induced processes as liquefaction, differential settle- 
ment, and slope failure. The potential for ground failure is governed by the 
presence of susceptible substrate materials such as water-saturated mud or 
granular materials. Earthquake-caused ground failure has been observed as far 
as 150 km from the earthquake source. 



Development of the Seismic Intensity Distribution Map for This Scenario 

In preparing a regional intensity map to be employed in the assessment of 
lifeline damage, CDMG selected the Evernden model (Evernden and others, 1973, 
1981; U.S. Geological Survey, 1981). This computer model calculates the 
ground shaking parameters of particle acceleration on a grid of reference 
points throughout a region employing equations which include the influence of 
distance from fault source, attenuation, and the geology of the substrate. 
The intensities are calculated by using an empirical relationship between 
acceleration and the Rossi-Forel (R-F) intensity scale. The Rossi-Forel scale 
was selected by Evernden because he interprets a rather straight-forward math- 
ematical relationship to exist between acceleration and this measure of inten- 
sity. The Modified Mercalli (MM) intensity scale, which was developed in 1931 
about half a century after the R-F scale, is extensively used today because it 
provides a classification of earthquake effects related to types of construc- 
tion. The R-F scale does not distinguish classes of buildings. In order to 
make the Seismic Intensity Distribution maps developed for this earthquake 
planning scenario as useful as possible, CDMG will publish a Modified Mercalli 
scale intensity map of the same area in the near future. Both scales are 
described and compared in the Appendix of this report. 



-37- 



The U.S. Geological Survey (USGS) has published a series of intensity maps 
for specific earthquakes, including the M 8.3 event on the northern San 
Andreas fault that is addressed in this scenario. The geologic substrate in- 
formation used in the USGS analysis was based upon 1:250,000 scale maps from 
the CDMG "Geologic Atlas of California." CDMG has modified this intensity map 
based on more detailed, additional geological information that was not includ- 
ed in the USGS analysis. 

The methodology of the Evernden model does not characterize the conse- 
quences of ground failure. In order to add this dimension to the CDMG inten- 
sity maps, information on local geology and ground water conditions was eval- 
uated in order to identify areas of potential ground failure. These areas are 
designated on CDMG's Seismic Intensity Distribution maps. Thus, the CDMG 
intensity map possesses intensity based upon the synthesis of both shaking and 
ground-failure effects. 



Areas of Potential Ground Failure in the San Francisco Bay Area 

In brief, the areas of high potential for ground failure include all Bay 
mud deposits (Nichols and Wright, 1971), all areas considered of high lique- 
faction potential by numerous authors, and most areas in which ground failure 
was noted in the 1906 earthquake (Youd and Hoose, 1978; Nason, 1980a, 1980b, 
1982) . These data were checked against detailed work in the literature and 
modified as indicated below for the nine Bay area counties. 



-38- 



CDMG recognized that landslide deposits are widely but sporadically dis- 
tributed on upland slopes, and that some of these, particularly in San Mateo, 
Marin, and Sonoma counties, will be activated by the scenario earthquake. 
Most of these deposits, however, are too small to be delineated individually 
at this map scale. 



Alameda County 

The data of Helley, Lajoie, and Burke (1972) was the prime reference. 
Younger fluvial deposits (Qyfo) north of Newark had historic liquefaction in 
the 1906 earthquake (Youd and Hoose, 1978). These deposits are considered 
subject to potential failure along with the underlying deposits (Qb) in the 
area extending east of Coyote Hills and south to the county line. Some parts 
of the older Bay mud (Qom) are included because there is historical evidence 
for failure near Alameda Creek (Youd and Hoose, 1978). Interfluvial basin 
deposits (unit Qb) are considered unlikely to fail in the region near the 
Oakland Coliseum. The margins of Alameda Island are included because they 
consist of loose, well-sorted dune sand (Helley, Lajoie, and Burke, 1972) 
which is near the water's edge. The central portions of the Island are not 
included because there was little evidence for liquefaction here in 1906 (Youd 
and Hoose, 1978). CDMG assumed that this unit (Merritt sand) does not under- 
lie any of the units north of the Bay Bridge or south of Bay Farm Island. 



-39- 



Contra Costa County 



The Richmond area is generalized, with units I and II of Bishop and others 
(1973) considered susceptible to ground failure. To the east of Richmond CDMG 
used unit III of the Contra Costa County Planning Department (1974). 



Marin County 

Rice (1973; 1975), Rice and others (1976), and Blake and others (1974) 
were used to delineate the areas of Bay mud likely to sustain ground failure. 



Napa County 



Sims and others (1973) was used to delineate the areas of Bay mud, 



San Francisco County 

CDMG used the data of Jacobs (1974), but excluded some dune sand at higher 
elevations southwest of Lake Merced. 



San Mateo County 

In addition to the areas delineated "moderate to locally high" in lique- 
faction potential by Woolfe and others (1975), the younger basin (Qb) and 



-40- 



beach deposits (Qs) of Lajoie and others (1974) were included. The alluvial 
fan deposits (Qy and Qyo) in the northeast corner of the county and in east 
Palo Alto are considered unlikely to fail (Lajoie and others, 1974) and were 
removed from consideration. 



Santa Clara County 

The historical data of Youd and Hoose (1978) was used to outline the area 
susceptible to liquefaction along Coyote Creek. In 1906, liquefaction was 
reported to the east of Guadalupe River, but not to the west. Thus, the 
Guadalupe River was chosen as the western boundary of the area influenced by 
liquefiable sands deposited by the Coyote Creek drainage. The potential for 
liquefaction is considered minimal in the rest of the county (James Berkland 
and Ben Patterson, geologists, Santa Clara County, oral communication, 1981). 



Solano County 

The data of Sedway /Cooke (1977) was used to define areas of potential 
ground failure due to liquefaction. A small area surrounding the Gold Hill 
Undercrossing was included as potentially liquefiable (see note H75 on Map HA). 



Sonoma County 



Blake and others (1974) was used to outline the areas of Bay mud, 



-41- 



Areas of High Water Table 

Areas of high water table (within 10 meters of the surface) were delineat- 
ed wherever possible, and the predicted intensity was increased by one R-F in- 
tensity unit in these areas as suggested by the U.S. Geological Survey (1981). 
Areas already designated intensity 9 (R-F) were not increased because intensi- 
ty 10 (R-F) was regarded principally as an indicator of ground failure rather 
than shaking. As mentioned, the potential for ground failure has to be 
assessed somewhat independently of the algorithm used to predict shaking 
intensity. 

The areas of high water table were delineated by extrapolating the data of 
Webster (1973) for the counties of San Mateo, Santa Clara, and Alameda. For 
Sonoma County, water table data was obtained from the California Department of 
Water Resources (1981). For the Livermore Valley in Alameda and Contra Costa 
counties, the estimates of Lunn (1982) were used for the current water table. 
For the Concord area it was estimated that a high water table would be 
encountered in those areas less than 40 feet above sea level. For the other 
counties, data on water table level was unavailable and, consequently, the 
"areas of high ground water" and areas of "moderate or unknown potential" for 
ground failure are identical 

Finally, the map was checked against the actual observed intensitites for 
the 1906 earthquake (Nason 1980a, 1980b, 1982; Lawson and others, 1908). 
Although there was general agreement between predicted and actual intensities 
for most of the Bay area, the damage to chimneys and unreinforced walls was 
greater in 1906 than the U.S. Geological Survey (1981) map predicted (7.5 R-F) 



-42- 



for areas in the far East Bay. In the Livermore Valley, for example, it was 
reported that 50 per cent of the chimneys were thrown down (Lawson and others, 
1908, p. 308). Other valleys in that area had similar types of damage, and on 
this basis CDMG assigned alluvium in the far East Bay a R-F intensity of 8 
even where it was unaffected by a high water table. 



-A3- 



-44- 



GENERAL CHARACTER OF THE SEISMIC INTENSITY DISTRIBUTION MAP 



The area encompassed in this planning scenario includes most of the more 
heavily populated areas of the San Francisco Bay region that would be signifi- 
cantly affected by the occurrence of the scenario earthquake, extending from 
Santa Rosa on the north to San Jose on the south. This scenario earthquake 
would, of course, cause substantial damage in many communities both north and 
south of the planning area that are within 50 kilometers or so of the surface 
rupture. In 1906, damage also occurred in many communities along the western 
margin of the San Joaquin Valley, although they are located at distances sig- 
nificantly greater than 50 kilometers from the surface rupture. These high 
intensities have generally been attributed to amplified shaking as a result of 
the high ground water levels which prevailed at the time of the 1906 event. 

As indicated previously, the earthquake selected for this scenario is the 
repeat occurrence of the San Francisco earthquake of April 18, 1906. This M 
8.3 event has its epicenter on the San Andreas fault very near San Francisco. 
Intense shaking is assumed to occur throughout the planning area for a period 
of 30-50 seconds. Surface rupture, resulting in a cumulative horizontal dis- 
placement across the fault of up to 6 meters, extends from San Juan Bautista 
to near Cape Mendocino, a distance of some 430 kilometers. No vertical fault 
slip occurs, and there is no secondary movement along any of the other faults 
in the region. Many aftershocks, with an occasional event in the M 6-7 range, 
continue for many weeks. 



-45- 



Predicted intensities resulting from this earthquake are shown on Map 
1-S. The areas of predicted intensity 9 (R-F) include most of the low-lying 
lands surrounding San Francisco and San Pablo Bays. This area of intense 
shaking encompasses a major portion of the more highly developed urban areas, 
including most of the Santa Clara Valley and portions of San Francisco, Oak- 
land, and virtually all of the other communities that border these Bays. In 
addition, portions of this area that are situated on Bay mud are susceptible 
to ground failures. This additional hazard is present in parts of Oakland, 
Alameda, Richmond, San Jose, and San Francisco, and to some extent affects all 
the communities located adjacent to the Bay. Intensity 9 (R-F) shaking is 
also forecast for the Santa Rosa-Sebastopol area. 

Intensity 8 (R-F) shaking is predicted for those portions of the East Bay 
communities where, in general, the water table is at a depth of more than 10 
meters from the surface, in the Diablo and Livermore Valleys, parts of the 
North Bay and, primarily because of their proximity to the fault, most of the 
San Francisco and Marin peninsulas. 

Most of the remainder of the planning area, generally the more mountain- 
ous, less-populated areas east of the Bay have a predicted intensity of 
7 (R-F) or less. 

These regional patterns associated with this scenario event are of suffi- 
cient plausibility to form a credible basis for evaluation of general affects 
upon lifelines that service the greater San Francisco Bay area. The discus- 
sions which follow highlight the anticipated regional consequences on these 
lifelines which are identified in the accompanying maps. 



-46- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIOS 

FOR LIFELINES 
IN THE SAN FRANCISCO BAY AREA 



The capacity for structures to withstand the effects of earthquake shak- 
ing, liquefaction, and related ground failure depends upon the soundness of 
each structure in relation to its geologic environment. Generally, structures 
within areas of less than intensity 8 (R-F) that are unaffected by ground 
failure are considered unlikely to sustain significant damage. "Significant 
damage" is defined here as damage that would render a structure impaired or 
unusable for 3 to 72 hours after the earthquake — the period most important for 
emergency response operations. 

The following earthquake planning scenarios for lifelines in the greater 
San Francisco Bay area are based upon an evaluation of the earthquake engi- 
neering literature, comments by numerous engineers and other public agency 
officials, and judgments by the authors. These damage scenarios will hope- 
fully stimulate those concerned with particular lifelines to offer additional 
insights that will serve to enhance earthquake preparedness efforts in this 
area. For example, critical corridors in transportation routes and other 
lifelines became apparent when such routes and lifelines were considered in 
light of the geologic input. At such critical locations, more extensive 
evaluations of the geologic hazards and potential damage to lifelines are in 
order. 



-47- 



-48- 



EARTHQUAKE PLANNING SCENARIO: HIGHWAYS 
Map 1-HA 



General Pattern 

Damage to the highway network will have its greatest impact on the San 
Francisco peninsula where vehicular traffic into and out of the City of San 
Francisco and much of San Mateo County may be impossible for many hours until 
one or more corridors become available. Use of the Golden Gate, San Fran- 
cisco-Oakland Bay, Richmond-San Rafael, and San Mateo bridges will be impossi- 
ble for an extended period. All peninsula routes west of the San Andreas 
fault will be closed. Some major arteries in Santa Clara County will be heav- 
ily damaged, but the many available alternate routes will permit rapid restor- 
ation of reasonable traffic flow. In the East Bay, routes closest to the Bay 
margin will be most seriously damaged, notably Route 17 between Richmond and 
San Leandro. Other major arteries closer to the Oakland Hills will be avail- 
able, however, subject to occasional detours. Major routes into the damaged 
areas from the east will be available, including Interstates 80 and 580 with 
connections to Interstates 680 and Route 24. In the North Bay the major pro- 
blems will be along U.S. 101 in the Santa Rosa area and in southern Marin 
County, where access to and from the area south of San Rafael will be severely 
limited. Experience has indicated, however, that alternative routes can gen- 
erally be rapidly developed and, while lengthy delays and detours will be com- 
mon, most of the initial confusion will be under control within a few days. 



-49- 



Description 

Immediately following the earthquake, 25 per cent of the freeways in the 
Bay Area will be impassable. Damage will be concentrated on the San Francisco 
peninsula and along the margins of the Bay where freeways are built upon fill- 
ed areas overlying Bay mud or upon liquefiable alluvial materials that will 
undergo ground failure. Egress and ingress in the Bay area will be restricted 
by landslides and cut-and-fill failures along routes through coastal moun- 
tains, particularly on the San Francisco peninsula. Although few landslides 
occurred in the East Bay hills during the 1906 earthquake, some of the many 
large cuts and fills constructed during recent years will experience some 
failures. 

The disruption produced by the earthquake will create gigantic traffic 
jams on heavily damaged U.S. 101 from Novato to San Jose and on Route 17 from 
Richmond to San Jose. Although the four principal Bay bridges will survive 
the shaking, extensive damage to their approaches will render them tem orarily 
impassable. Both tunnels under the estuary to Alameda will be closed, but at 
least one of the bridges to the island will remain open. Travel on surface 
streets in cities will be restricted because of fires, blockades, and rubble. 

Within the first 12 hours emergency routes will be cleared along major 
city streets. For example, major north-south access can probably be opened 
along Route 82 (El Camino Real) on the San Francisco peninsula and Route 123 
(San Pablo Avenue) and Interstate 580 in the East Bay. These routes will be 
essential to emergency traffic between areas sustaining heavy casualties and 
hospitals surviving the earthquake. High priority will also be given to 



-50- 



routes to airports and heliports for bringing in rescue personnel and 
equipment. 

Within 24 hours, access from San Francisco to Marin County can be restored 
when detours become available at the south approach to the Golden Gate bridge. 
A major source of post earthquake assistance will be the Walnut Creek area, 
but access to this area is highly dependent upon the integrity of Route 24, 
and, in particular, the Caldecott Tunnel, which is expected to remain open for 
emergency traffic although landslides may restrict use of some lanes near the 
east portals. 

Within 36 hours, additional routes should become usable. For example, 
Route 17 from San Jose to Santa Cruz should be open to singlelane traffic. In 
Sonoma County, a few damaged bridges on U.S. 101 can be temporarily strength- 
ened to carry limited truck traffic. However, because of severe damage to the 
Bay bridge approaches, and to freeways built along the margins of the Bay, 
these major arteries will not be available within the first 72 hours. Accord- 
ingly, response planning should not rely upon these major routes for emergency 
use. 

The primary contribution regarding the integrity of major highways was 
provided by the California Department of Transportation (CDOT, 1981) with the 
caveat that "this scenario is presented for planning purposes only and may be 
overly pessimistic in its overall impact." Thus, where numerous bridges, 
highways, and other facilities are located in areas where failures could 
occur, CALTRANS has noted the route as closed, even though it is unlikely that 
the entire route segment would be impassable for the time periods specified. 



-51- 



The alternative is to ignore some possibilities in an arbitrary way. It is 
important in emergency planning to have contingency plans to deal with all 
plausible possibilities which may significantly impair ground transportation 
during the important 72-hour period following this catastrophic event. CDMG 
worked with the CALTRANS staff to relate geologic conditions and seismic 
intensity to highway effects. 

In certain instances the CALTRANS assessment was modified when additional 
geologic data and other assessments indicated that this was appropriate. For 
example, CDMG considered the shaking at the east end of the Caldecott Tunnel 
to be insufficient to cause landslides large enough to block all lanes and all 
three tunnels through the East Bay hills. 



Planning Insights 

Emergency planners need to identify major emergency corridors that can be 
most readily opened immediately following the earthquake. In contrast to some 
segments of the freeway system which are above or below grade with many struc- 
tures subject to damage, alternative emergency routes should be selected which 
are at grade, wide, not likely to be significantly affected by fallen power- 
lines or other obstructions, and not flanked by larger buildings that are 
likely to be damaged. Selection of emergency corridors is especially impor- 
tant in the urban areas of San Francisco, San Mateo, and Santa Clara counties 
and in Oakland, Berkeley, and Alameda in the East Bay, where significant 
damage is expected. Wherever possible, alternate corridors should be estab- 
lished so that flexibility is achieved. 



-52- 



The utilities and local government agencies should identify all such 
installations and facilities that they will need to inspect, repair, operate, 
or otherwise have access to in this emergency. 

Emergency planners need to examine available routes to critical facili- 
ties, assess the potential for damage, and identify the most probable access 
routes. Critical facilities include communication centers, hospitals, air- 
ports, heliports, staging areas, fuel storage sites, and other locations 
essential to emergency response. 

Access to the area with supplies and personnel from cities in the Great 
Valley and southern California will be available. Highway emergency-response 
plans should be coordinated with air, rail, and marine transport scenarios in 
order to optimize plans for integrated transportation capability. Access to 
the stricken area and travel within it will be difficult and will be limited 
to the highest emergency priorities. 



Recommended Further Work 

Assessment of highway performance and identification of alternative emer- 
gency routes is especially important in all areas where major damage is a 
reasonable expectation. 



-53- 



HIGHWAYS 



MAP NOTATIONS 



(See Map 1-HA.) 



NO. ROUTE COUNTY 

HI U.S. 101 - Golden Gate Bridge San Francisco 

Closed for 24 hours . 

The bridge itself, like the other Bay crossings, will withstand the shak- 
ing. Following a post-earthquake inspection, the bridge will be avail- 
able for pedestrian traffic, providing access is available on both ends. 
CALTRANS estimates that, for vehicular traffic, it will be closed due to 
approach failures at the south end, but can be opened to traffic in 
24 hours (CDOT, 1981). The Golden Gate Bridge approaches on the north 
side are vulnerable to major landslides, particularly in the wet season, 
and virtually complete halt to bridge traffic is possible from landslides 
(Algermissen and others, 1972, p. 162). 

H2 U.S. 101 - South approach to the Golden Gate Bridge San Francisco 

Closed for 24 hours . 

Bridge access will be cut-off by collapse of the Marina Viaduct and soil 
failures at the Toll Plaza area. Access can be restored via Lincoln 
Blvd. South within 24 hours (CDOT, 1981). 

H3 Interstate 80 - S.F. /Oakland Bay Bridge San Francisco/Alameda 

Closed for over 72 hours . 

Blocked at the east end by extensive soil failures and cannot be opened 
within 72 hours (CDOT, 1981). Following a post-earthquake inspection, 
the bridge will be usable for pedestrian traffic, providing access is 
available at both ends. The earth fills of the east approach appear to 
be subject to extreme slippage and differential settlements. The elevat- 
ed approach structures on the west end of the Bay Bridge are also subject 
to failure based on San Fernando experience. Total collapse can be dis- 
counted (Algermissen and others, 1972, p. 161). 

H4 Route 1 San Francisco 

Open . 
Open with some delays (CDOT, 1981). 



-54- 



H5 Interstate 280/U.S. 101 Interchange San Francisco 

Closed for 36 hours . 

Soil failures and bridge collapses; detour can be made available through 
the area in 36 hours (CDOT, 1981). 

H6 U.S. 101 San Francisco 

Closed for over 72 hours . 

Blocked from Interstate 280 northward and cannot be opened within 72 
hours (CDOT, 1981). 

H7 Interstate 280-Potrero Hill slide San Francisco 

Closed for over 72 hours . 
Cannot be opened within 72 hours (CDOT, 1981). 

H8 Downtown Freeway System San Francisco 

Closed for over 72 hours . 

Unusable within 72 hours (CDOT, 1981). The James Lick Skyway is built 
upon 5-15 feet of very loose fine to medium sand artificial fill over 20 
to 70 feet of Bay mud. The fill is dune sand and the 1906 ground failure 
zone was between 4th and 6th Streets (Youd and Hoose, 1978, p. 43). 

H9 Interstate 80 - Hoffman Avenue Overcrossing Alameda 

Closed for 24 hours . 

Closed due to soil and bridge failures; open to limited traffic in 24 
hours (CDOT, 1981). 

H10 Interstate 80 - University Ave. Overcrossing Alameda 

Closed for 24 hours . 

Closed due to soil and bridge failures; open to limited traffic in 
24 hours (CDOT, 1981). 

Hll Interstate 80 - Emeryville Alameda 

Closed for up to 36 hours . 

Generally open with delays and obstructions (CDOT, 1981). Closure due to 
damage described in notes H9 and H10, and other locations by ground 
failure. 

H12 Webster St. and Posey Tubes Alameda 

Closed for over 72 hours . 

Closed to traffic both ways. No possibility of opening within 72 hours 
(CDOT, 1981). 



-55- 



H13 Route 17 



Alameda 



Closed for up to 36 hours . 

The hydraulic fills used to construct miles of freeway along the east 
shore of the Bay in Alameda County may liquefy during heavy shaking, with 
long sections becoming totally impassable (Algermissen and others, 1972, 
p. 159). Generally open with delays, obstructions and detours (CDOT, 
1981) . Many bridges along Route 17 will be heavily damaged and can only 
carry light traffic (no trucks). A few select bridges can be strengthened 
to carry limited truck traffic in 36 hours (CDOT, 1981). The elevated 
section through downtown Oakland is expected to be extensively damaged. 
Liquefaction and related ground failures will occur between the Bay 
Bridge approach and the Oakland Coliseum. 



H14 Route 17 - Oakland Airport access 
Closed for 36 hours. 



Alameda 



Improved airport access at Hegenberger Rd. and Davis Streets could be 
obtained in 36 hours (CDOT, 1981). Single-lane traffic only at 98th 
Avenue (CDOT, 1981). 



H15 Route 17 - High St. Interchange Alameda 

Closed for over 72 hours . 
Closed (CDOT, 1981). 

H16 Route 17 - Hegenberger Road Interchange Alameda 

Closed for over 72 hours . 
Improved airport access may be obtained in 36 hours (CDOT, 1981). 

H17 Route 17 - Davis St. Interchange Alameda 

Closed for over 72 hours . 
Improved airport access may be obtained in 36 hours (CDOT, 1981). 

H18 Route 92 - San Mateo Bridge, east approach Alameda 

Closed for over 72 hours . 

Closed due to extensive soil failure at the east approach. No possibili- 
ty of opening within 72 hours (CDOT, 1981). San Mateo Bridge will be out 
of operation for an indefinite period due to direct damage to the bridge 
structures and/or approach problems (Algermissen and others, 1972, p. 
162). Following a post-earthquake inspection, the bridge will be usable 
for pedestrian traffic, providing access is available at both ends. 



-56- 



H19 Route 84 - Dumbarton Bridge - east approach Alameda 

Closed for up to 12 hours * 

Open to one-way traffic with delays due to soil failures at east end 
(CDOT, 1981). 

H20 Route 84 - Niles Canyon Road Alameda 

Closed for over 72 hours . 

Closed due to slides and bridge failures. This section cannot be opened 
in 72 hours (CDOT, 1981). 

H21 Route 84-Sunol to Livermore Alameda 

Closed for over 72 hours . 

Closed by slides and collapse of the Arroyo Valley Bridge. No detour 
possible within 72 hours (CDOT, 1981). 

H22 Interstate 580 Alameda 

Open . 
Generally open with delays and obstructions (CDOT, 1981). 

H23 Interstate 680 Alameda 

Open . 
Generally open with delays and obstructions (CDOT, 1981). 

H24 Route 238 Alameda 

Open . 
Generally open with delays and obstructions (CDOT, 1981). 

H25 Caldecott Tunnel Contra Costa 

Open within 12 hours . 

Closed by a partial collapse and slides at east end (CDOT, 1981). We 
believe this assessment to be overly pessimistic. Shaking is likely to 
be less than intensity 8 (R-F) , suggesting that at least one tunnel and 
one lane will be open to emergency traffic within the first few hours. 
"As indicated, a major source of post earthquake assistance will be the 
Walnut Creek area. Therefore, it is imperative that alternate routes 
such as Canyon Road be explored for readily available access, other than 
the Caldecott Tunnel" (McCarty, 1981). "We have no comment on the 
tunnel. The highway should not be totally closed in Contra Costa County 
(east tunnel portal to Walnut Creek)" (Dehaesus and Nelson, 1981). 



-57- 



H26 U.S. 101 San Mateo 

Closed for over 72 hours . 

Closed for a major portion of the distance from Menlo Park, to Candlestick 
Park, Route 101 cannot be opened within 72 hours (CDOT, 1981). "U.S. 101 
between Candlestick Point and San Bruno will be out of service due to 
land failure" (Algermissen and others, 1972, p. 162). Moderate to high 
liquefaction potential along most of the length (Woolfe and others, 1975, 
p. 93). Along U.S. 101 south of Candlestick Point in San Francisco to 
San Bruno, major land slips or movements are distinctly possible in heavy 
ground motion, and major stretches of this freeway can be under water or 
badly damaged due to soil movements (Algermissen and others, 1972, p. 
159). 

H27 U.S. 101 - San Francisco International Airport Access San Mateo 

Closed for less than 48 hours . 

Route 101 access to the San Francisco International Airport is shut off. 
Access may be re-established in about 48 hours via Route 82 (CDOT, 1981). 

H28 Route 1 - Devil's Slide San Mateo 

Closed for over 72 hours . 
This notorious slide will close Route 1 even with moderate shaking. 

H29 Route 1 - San Andreas Fault Crossing San Mateo 

Closed for over 72 hours . 

This route crosses the San Andreas fault near the intersection with Sky- 
line Blvd. (Woolfe and others, 1975, p. 93). Though the 5 meters of 
right lateral offset could be repaired within 12 hours, landslides along 
the coast to the south will close the remainder of the route for at least 
72 hours, (see note H66). 



H30 El Camino Real (Route 82) Santa Clara/San Mateo 

Open . 

Open with many major detours and delays to avoid collapsed buildings and 
bridges (CDOT, 1981). Low liquefaction potential (Woolfe and others, 
1975, p. 94). It appears that the brunt of post-earthquake traffic will 
need to be borne by El Camino Real (Route 82), although here, too, damag- 
ed and/ or destroyed culverts crossing underneath the roadbed may necessi- 
tate local traffic diversions (Woolfe and others, 1975, p. 95). 

H31 Great Highway San Francisco 

Closed for at least 72 hours . 

Conditions for liquefaction are present (Jacobs, 1974, p. 10a). Parts of 
the highway will be destroyed by liquefaction of beach sands. 



-58- 



H32 Route 92 San Mateo 

Closed for over 72 hours . 

Closed from Half Moon Bay to Route 280 due to slides and faulting and 
cannot be opened within 72 hours (CDOT, 1981). 

H33 Route 35 San Mateo 

Closed for over 72 hours . 

Closed and cannot be opened within 72 hours (CDOT, 1981). Northerly por- 
tion crosses San Andreas fault near King Drive (Daly City); landslide 
potential south of Route 84 (Woolfe and others, 1975, p. 94). Extensive 
damage due to fault rupture will occur throughout the northern portion of 
this route. 

H34 Interstate 280 San Mateo 

Closed for less than 36 hours . 

Closed at Route 92 by a bridge collapse. A detour can be made around this 
area in 8 hours (CDOT, 1981). Significant landslide hazard (Woolfe and 
others, 1975, p. 93). Although this route will be unaffected by fault 
rupture, its proximity to the fault may subject it to certain near-field 
effects that are not predictable. 

H35 Interstate 380 San Mateo 

Open . 

Closed at U.S. 101; but open from Route 280 to Route 82 (CDOT, 1981). Low 
liquefaction potential (Woolfe and others, 1981, p. 93). Detours can be 
made available around the affected interchanges. 

H36 Interstate 380/U.S. 101 Interchange San Mateo 

Closed for over 72 hours . 
It will not be possible to clear the damage within 72 hours (CDOT, 1981). 

H37 Route 37 Napa/Sonoma/Marin 

Closed for over 72 hours . 

Closed between Sears Point and Vallejo due to extensive settlement and 
shift of the roadway. No possibility of opening within 72 hours (CDOT, 
1981). The same applies to Route 37 between Sears Point and U.S. 101 
where extensive liquefaction will occur between Sears Point and the 
Petaluma River (S.J. Rice, personal communication, 1981). 



-59- 



H38 U.S. 101 - north of San Rafael Marin/Sonoma 

Open, with some portions closed for up to 12 hours . 

Many overcrosslngs over U.S. 101 are standing but are heavily damaged and 
can carry only light traffic (no trucks) . A few select bridges can be 
strengthened to carry limited truck traffic in 36 hours (CDOT, 1981). 
The heaviest damage will be concentrated in Petaluma and between Cotati 
and Santa Rosa. Liquefaction damage will close the interchanges with 
Routes 17 and 37 for up to 12 hours. 

H39 Route 84 San Mateo 

Closed for over 72 hours . 

Closed from San Gregorio to Woodside due to extensive slides and cannot 
be opened within 72 hours (CDOT, 1981). High landslide potential (Woolfe 
and others, 1975, p. 94). The mountainous areas of San Mateo County had 
numerous landslides in the 1906 event, which followed a March of record 
rainfall (Youd and Hoose, 1978). 

H40 Route 1 Marin 

Closed for over 72 hours . 

Closed at numerous locations due to slides, slipouts, and bridge fail- 
ures. No possibility of opening within 72 hours (CDOT, 1981). 

H41 Route 17 - Richmond/San Rafael Bridge approach Marin 

Closed to vehicles for at least 72 hours . 

Heavily damaged and settled. No possibility of opening within 72 hours 
(CDOT, 1981). 

H42 U.S. 101 Marin 

Closed for 12 hours . 

South of San Rafael U.S. 101 is closed by pavement breaks and settlements 
and by one bridge collapsed over the freeway. Repairs and detour can be 
made in 12 hours. Many bridges over and on U.S. 101 are damaged and cap- 
able of carrying light traffic only (no trucks) . A few select bridges 
can be strengthened to carry limited truck traffic in 36 hours (CDOT, 
1981). 

H43 Geary Blvd. San Francisco 

Open . 

A major E-W route connecting Ocean Beach with downtown. The route has no 
liquefaction problems and a possible landslide (Jacobs, 1974, p. 10a) can 
be avoided by a detour. 



■60- 



H44 Route 17 - Richmond/ San Rafael Bridge approach Contra Costa 

Closed for at least 72 hours . 

Heavily damaged and settled. No possibility of opening within 72 hours 
(CDOT, 1981). 

H45 Interstate 680 - Carquinez Bridge approach Contra Costa 

Closed for less than 12 hours . 

Damaged but opened within 8 hours after approach work and inspection 
(CDOT, 1981). 

H46 Interstate 680 - Benicia/Martinez Bridge approach Contra Costa 

Closed for less than 12 hours . 

Damaged but opened within 8 hours after approach work and inspection 
(CDOT, 1981). 

H47 Interstate 680 - south of Benicia/Martinez Bridge Contra Costa 

Closed for less than 12 hours . 

Closed due to extensive soil failure. This route may be opened to 

fourwheel-drive vehicles in two hours and opened to limited traffic in 

12 hours (CDOT, 1981). This area is filled marsh (Nichols and Wright, 
1971). 

H48 Route 4 Contra Costa 

Closed for less than 12 hours . 

Closed between Interstates 80 and 680 due to extensive soil failure and 
collapse of Alhambra Avenue UC (undercrossing) . No possibility of opening 
within 72 hours (CDOT, 1981). "We doubt that Route 4 will be totally 
closed by landslides; one lane should remain open or can be readily open- 
ed (less than 3 hours). Even if Alhambra Avenue UC collapses, alternate 
ramps in the interchange should be available" (Dehaesus and Nelson, 1981). 

H49 Interstate 680 - Benicia Viaduct Solano 

Open . 

The footings are in bay marsh (Nichols and Wright, 1971), but apparently 
founded in nonliquef iable material. 

H50 Interstate 80 - Willow Ave. UC Contra Costa 

Closed for less than 12 hours . 

Damaged and closed to all traffic for inspection. Detour available 
through Pinole. May be open to single-lane traffic in 3 hours (CDOT, 
1981). 



-61- 



H51 Interstate 80 - Appian Way Hilltop Slide Contra Costa 

Open . 

This landslide will restrict traffic on Interstate 80 to one lane each 
way. May be opened up to two lanes each way in 48 hours (CDOT, 1981). 

H52 Interstate 680 Contra Costa 

Open . 

Many overcrossings will be standing but these will be heavily damaged and 
can carry only light traffic (no trucks) • A few select bridges can be 
strengthened to carry limited truck traffic in 36 hours (CDOT, 1981). 
This may be an overly pessimistic assessment since predicted shaking in 
this area is only intensity 8 (R-F) . "We do not believe soil failures 
will close 1-680" (Dehaesus and Nelson, 1981). 

"From the Caldecott tunnel an alternate route to 1-680 northbound is 
available over Pleasant Hill Road-Taylor Blvd. Expressway. The only ser- 
ious restriction may be Pleasant Hill Road OC (Taylor Blvd.). From the 
foundation and approach fill standpoint the bridge will remain service- 
able or can be readily restored to service, and in any case the south- 
bound 2 lanes would not be affected except by minor rockfalls. The route 
should be open from Pleasant Hill Road interchange with Highway 24 to 
Willow Pass Road OC (over crossing) and Taylor Blvd. junction on 1-680 in 
Concord" (Dehaesus and Nelson, 1981). 

H53 Route 123 - San Pablo Ave., south of Cutting Blvd. Contra Costa/Alameda 

Open . 

Primary N-S emergency route in Berkeley-Albany area. Areas of liquefac- 
tion (Bishop and others, 1973) may require detours further east. Severe 
congestion is expected to affect San Pablo Avenue (Dehaesus and Nelson, 
1981). 

H54 San Pablo Dam Road Contra Costa 

Closed for less than 12 hours . 

Although there are numerous landslides between San Pablo Dam and points 
further east (Bishop and others, 1973), the shaking intensity will not 
produce more than small cut and fill failures. 



■62- 



H55 Route 17 - Hoffman Ave. off ramp to Richmond- Contra Costa 

San Rafael Bridge 

Closed for more than 72 hours . 

High liquefaction potential for all but segment through San Pablo Hills 
(Bishop and others, 1973). 

H56 Route 123 - San Pablo Ave., north of Cutting Blvd. Contra Costa 

Open . 

Primary N-S emergency route through Richmond. There is potential for 
liquefaction between Cutting Blvd. and Interstate 80-San Pablo Blvd. 
interchange and again at San Pablo Creek (Bishop and others, 1973). 

H57 Route 17 Santa Clara 

Closed for more than 72 hours from Fremont to San Jose and for less than 

36 hours from San Jose to Santa Cruz . 

According to CDOT (1981), this route will be closed from Milpitas to 
Santa Cruz due to extensive soil and bridge failures. May be opened to 
single-lane limited traffic in 36 hours, but Louis (1981) states: "While 
we have no knowledge of the performance of the structures, in general the 
foundation soils and the cut slopes are expected to experience only local 
and relatively minor distress." 

H58 Route 9 Santa Clara 

Closed for at least 72 hours . 
Closed and cannot possibly be opened within 72 hours (CDOT, 1981). 

H59 Route 35 Santa Clara 

Closed for at least 72 hours . 
Closed and cannot possibly be opened within 72 hours (CDOT, 1981). 

H60 Route 237 - Milpitas to Mountain View Santa Clara 

Closed for at least 72 hours . 

Closed due to massive liquefaction failures. This route cannot be opened 
within 72 hours (CDOT, 1981). Substandard overcrossings at the East 
Mountain View overhead and Mountain View railroad overhead (Eggleston, 
1980). Possible liquefaction may occur along most of the route (County of 
Santa Clara Planning Department, 1976, p. 53). Louis (1981) states that 
site-specific studies suggest that liquefaction is most likely to be a 
minor problem and differential settlement is likely to be more trouble- 
some. Damage to Route 237 will be confined to the section east of the 
Guadalupe River. 



-63- 



H61 El Camino Real (Route 82) Santa Clara 

Open . 

Open with many major detours and delays to avoid collapsed buildings and 
bridges (CDOT, 1981). Substandard overcrossings at Blossom Hill Road and 
Hillsdale Avenue-Capital Expressway (Eggleston, 1980). 

H62 Interstate 280 - San Jose to Los Altos Santa Clara 

Open . 

Open with some obstructions and delays (CDOT, 1981). Possible liquefac- 
tion hazard near Cupertino (County of Santa Clara Planning Department, 
1976, p. 53). Site-specific studies suggest very shallow groundwater and 
liquefiable materials may result in local failures of fills. Some cut 
slopes may also experience local failures (Louis, 1981). 

H63 U.S. 101 - Gilroy to San Jose Santa Clara 

Open . 

Open (CDOT, 1981). Same comments as note H62; however, this route does 
not have the number of embankments that are found on Interstate 280 
(Louis, 1981). 

H64 U.S. 101 - San Jose to Menlo Park Santa Clara 

Closed for over 72 hours . 

Closed due to bridge and highway failures. This portion cannot be opened 
within 72 hours (CDOT, 1981). Possible liquefaction hazard present along 
most of length (County of Santa Clara Planning Department, 1976). Site- 
specific studies do not indicate problems in the foundation soils, and 
differential settlement is likely to be the most significant problem 
(Louis, 1981). See list of 29 substandard overcrossings (between San 
Jose and South San Francisco) in Eggleston (1980). 

H65 Interstate 680 (south) Santa Clara 

Open to U.S. 101 south, but closed between U.S. 101 and Route 82 for less 

than 12 hours . 

Possible liquefaction along this route (County of Santa Clara Planning 
Department, 1976, p. 53). Route contains few, if any, slopes greater 
than 30% (p. 25). "Site specific studies indicate no soils or foundation 
problems along this alignment" (Louis, 1981). 

H66 Route 1 - Daly City to Santa Cruz San Mateo 

Closed for over 72 hours . 

Closed from Daly City to Santa Cruz due to slides and slipouts. No pos- 
sibility of opening within 72 hours (CDOT, 1981). 



-64- 



H67 Route 13 - Route 24 to Interstate 580 Alameda 

Open . 

Numerous alternate routes are available. This route parallels the 
Hayward fault. However, there was no sympathetic movement along the 
Hayward Fault during the 1906 event (Lawson and others, 1908) and none is 
assumed in this scenario. 

H68 Route 24 - Caldecott Tunnel to Route 17 Alameda 

Open . 
Numerous alternate routes are available. 

H69 Claremont Ave. - Fish Ranch Road Alameda 

Open . 
Alternate route to the Caldecott Tunnel (Route 24). 

H70 Bridge Access to the City of Alameda Alameda 

One, or more, open . 

CDOT did not give an assessment of the Route 62 bridge crossing of San 
Leandro Channel to the City of Alameda. Also, no assessment is made of 
the bascule bridges maintained by Alameda County. Without these assess- 
ments the potential for isolation of the City of Alameda is unknown 
(Lanferman and Danehy, 1981). Of these four bridges, we consider it 
unlikely that all will be closed. 

H71 Route 4 - Concord to Antioch Contra Costa 

Open to Route 160 . 

H72 Route 160 Sacramento 

Open from Route 4 to Antioch Bridge. Closed from Antioch Bridge to 

Brannan Island . 

Due consideration should be given to the levees in the Delta complex. 
Some of these facilities carry vital transportation routes and are cer- 
tainly subject to liquefaction (Stiver, 1981). 

H73 Route 29 Napa 

Open. 



-65- 



H74 Route 12 Sonoma/Napa 

Open . 

H75 Interstate 680 - Gold Hill Undercrossing Solano 

Open , 

There is evidence for lateral spreading northwest of the undercrossing, 
and this, combined with data showing that (a) the water table was at 
7 feet in 1963 and (b) a loose brown silty gravelly sand layer lies 
between depths of 21 and 24 feet at the undercrossing may indicate a liq- 
uefaction hazard in the area. The bridge, however, is built on steel 
pipe piles founded in nonliquef iable material (A. F. Goldschmidt, 
Engineering Geologist, CALTRANS, oral communication 1982). 



-66- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIO: AIRPORTS 
Map 1-HA 

General Pattern 

Emergency air transport into the stricken region from the outside is vit- 
al to response activities during the first 72 hours following the earthquake. 
Because of expected damage to major airport facilities, notably the runways 
and land access routes, San Francisco International and Metropolitan Oakland 
International airports, as well as Alameda Naval Air Station and Hamilton 
Field, will be unavailable for major airborne relief operations (C-141 air- 
craft and massive logistics). San Jose Municipal, Hayward Municipal, and 
Buchanan Field will be available with limitations. Thus, delivery of massive 
emergency aid from outside the area will be hampered by the lack of a close-in 
major facility. Travis Air Force Base near Fairfield becomes the logical 
choice for this operation. 



Description 

Four of the eight major airports most accessible to the stricken areas 
are built upon fill overlying soft Bay mud. A fifth is in an area of high 
water table and is subject to intense shaking. Intense shaking and subsequent 
ground failure along the margins of San Francisco Bay will make runways locat- 
ed in these areas unusable. 



-67- 



According to Algermissen and others (1972, p. 169), "San Francisco Inter- 
national Airport, Oakland International Airport, and Alameda Naval Airbase 
Airport are in regions of structurally poor ground (Bay mud areas), and Hamil- 
ton Air Force Base Airport soils are open to some question from a structural 
standpoint. In the event of high intensities at these four airports, the run- 
ways will be considered to be badly broken for planning purposes even though 
experience does not fully confirm this. The runways on the other airports are 
expected to remain in operation, or become operational again in hours." 

Only San Jose Municipal, Hayward Municipal, and Buchanan Field (near Con- 
cord) have a reasonable chance of surviving the earthquake without serious 
disruption of runway integrity. Buchanan Field will be subjected to less 
shaking than the others but, similar to Hayward Municipal Airport, it can sup- 
port only the smaller C-130 aircraft used in emergency operations. (C-130's 
require at least 5,000 ft. of runway and pavement strength to withstand 
130,000 lb. wheel weights (dual tandem)). Only San Jose Municipal Airport 
remains as a close-in airport that is large enough for C-141 aircraft. 
(C-141's require at least 5,000 feet of runway and pavement strength to with- 
stand 250,000 lb. wheel weights (dual)). Detailed engineering-geologic 
studies of these three airports, particularly San Jose Municipal Airport, may 
suggest warranted improvements in emergency handling facilities. Outlying 
airports such as Travis Air Force Base, and the Sacramento and Stockton Air- 
ports, will be available, but the response effort will be delayed because of 
the necessity to transport cargo a greater distance to the stricken area. 



-68- 



Planning Insights 

Airborne transport will play a vital role in the transport of people and 
materiel to and from the stricken areas and in search and rescue, damage 
assessment, and many other emergency response efforts. Pre-selection of one 
or more air cargo delivery facilities will influence planning for distribution 
of material by helicopter, highway, rail, ane marine transport. Integrating 
these various delivery systems to accomplish this mission will be challenging. 
Use of helicopters within the heavily damaged areas is seen as an extremely 
important function requiring appropriate planning. 



Recommended Further Work 

Secondary airports for distribution of supplies and equipment need to be 
evaluated in terms of auxiliary electrical power supply, integrity of airport 
buildings, and vulnerability of access routes in order to finalize transporta- 
tion plans. The vulnerability of runways at San Jose Municipal Airport, in 
particular, needs to be evaluated further since more data can either confirm 
or modify the conclusions presented in this report. A plan of action, with 
established equipment and supplies and listed tangible resources for a sus- 
tained effort, should be prepared. Facilities suitable for helicopter opera- 
tions within the stricken area should be selected, particularly in San Fran- 
cisco, San Mateo, and southern Marin County. A statewide system of priority 
identification (see Walford and Kermit, 1981) should be established for 
personnel who are essential to the emergency-response efforts at airports such 



-69- 



as Buchanan Field and San Jose Municipal Airport that are likely to have run- 
way integrity following the earthquake. Such a system should assure that 
these personnel can secure official assistance in getting to their areas of 
responsibility when access is restricted due to traffic jams or other block- 
ages. Developing such a system is of the highest priority because the exper- 
tise of these personnel is crucial to the planned emergency response. 



AIRPORTS 



MAP NOTATIONS 



(See Map 1-HA.) 



NO. AIRPORT COUNTY 



Al San Francisco International Airport (SFO) San Mateo 

Closed for over 72 hours . 

SFO is built entirely on fill (Nichols and Wright, 1971), and the water 
table is within 5 feet of the surface (Webster, 1973). The SFO area was 
filled by using construction procedures designed to displace the Bay mud 
(R.D. Borcherdt, personal communication, 1981), but its effectiveness in 
preventing runway damage during large earthquakes remains to be estab- 
lished. According to Algermissen and others (1972, p. 169), SFO will be 
closed for several weeks, and practical land access will not exist to San 
Francisco Airport due to freeway and highway damage which will effective- 
ly isolate the airport and nearby facilities. 

A2 Metropolitan Oakland International Airport (OAK) Alameda 

Closed for over 72 hours . 

OAK is built entirely on Bay fill (Nichols and Wright, 1971), and the 
water table is within 5 feet of the surface (Webster, 1973). It is not 
likely to be useable for large transport cargo aircraft. According to 
Algermissen and others (1972, p. 169), OAK will be closed for no longer 
than one week. 



-70- 



A3 Alameda Naval Air Station (NAS) Alameda 

Closed for over 72 hours . 

Alameda NAS is built entirely on Bay fill (Nichols and Wright, 1971), and 
the water table is within 5 feet of the surface (Webster, 1973). It is 
unlikely to be useable for large transport cargo aircraft. According to 
Algermissen and others (1972, p. 169), Alameda NAS will be closed for no 
longer than one week. 

A4 Hamilton Field Marin 

Closed for over 72 hours . 

Hamilton Field is built entirely on Bay fill (Nichols and Wright, 1971), 
and the runway is only about 2 feet below sea level. According to Rice 
(1973), the airport lies in an area of major damage, which in this set- 
ting is likely to result from secondary effects of the earthquake vibra- 
tions, especially from differential settlement and disruption of the fill 
caused by accelerated compaction or lateral flow of the mud beneath the 
fill. See also Rice (1975) and Rice, Smith, and Strand (1976). Accord- 
ing to Algermissen and others (1972, p. 169), Hamilton Field will be 
closed for no longer than one week. 

A5 San Jose Municipal Airport Santa Clara 

Open for limited use . 

To estimate the conditions of the runways following the scenario earth- 
quake with any confidence would require more analysis. In the mea time, 
for planning purposes the facility should not be depended upon for access 
to the region from the outside. Webster (1973) states that the water 
table at this location is mostly at depths greater than 20 feet, but 
Laird and others (1979, p. 42) indicate the water table is within 10 feet 
of the surface. According to Troup (1981) "water table depths vary 
throughout the Airport. A soils investigation by Woodward-Clyde Consul- 
tants on May 1, 1981, located water table depths in the 15- to 16-foot 
range with one test hole showing a depth of only 13 feet." Perkins and 
others (1981) state that this is not an area of high liquefaction poten- 
tial, but according to the County of Santa Clara Planning Department 
(1976, p. 53) it is in an area of possible liquefaction. Within the 
first 4-12 feet, only one of 150 borings had liquefiable unconsolidated 
material at or near the runway (Troup, 1971). According to Troup (1981), 
test borings do not greatly indicate liquefaction potential. However, 
the existence of compressible materials underlying the runways and the 
varying structural sections due to stage construction of the runways sup- 
port a potential problem of differential settlement. Therefore, it is 
possible that the runways would not be open or available for emergency 
purposes. The Airport Terminal building was designed to support a second 
sLury which was never built. However, an analysis based on new earth- 
quake standards has not taken place to determine the adequacy of the 
structure (Troup, 1981). There is a generator for indoor lighting, etc., 
but none for fuel pumps (Verne B. Troup, Deputy Director Airport Planning 
and Development, oral communication, 1981). Runway length is 8,900 feet, 



-71- 



which is sufficient for large-scale rescue operations. According to 
Algermissen and others (1972, p. 169), the runways at San Jose are 
expected to remain in operation, or become operational again in hours. 

A6 Moffett Field Naval Air Station Santa Clara 

Open for limited use . 

The water table is within 5 to 10 feet of the surface (Webster, 1973). 
Only the northern tip of the runway is built upon Bay fill (Nichols and 
Wright, 1971), but liquefaction may be likely at the site (Perkins and 
others, 1981). The longest runway is 9,000 ft. and maximum allowable 
wheel weight is 257,000 lb. gross load weight (dual tandem wheel load 
capacity) which is sufficient for C-141 aircraft. It is asphalt/ con- 
crete. The nearness of this airport to the fault, the airport's associa- 
tion with Bay mud, and its location in an area of high water table all 
indicate that it might be disrupted considerably during the earthquake. 
For planning purposes, this facility should not be considered a reliable 
means of air-transport access unless suitability is established by fur- 
ther work. However, according to Algermissen and others (1972, p. 169), 
the runway is "expected to remain in operation, or become operational 
again in hours." 

A7 Hayward Municipal Airport Alameda 

Open for limited use (C-130 aircraft or smaller) . 

The water table here is at depths of 5 to 20 feet (Webster, 1973), the 
airport is not built on Bay mud (Nichols and Wright, 1971), and the 
liquefaction potential is not high (Perkins and others, 1981). The 
length is sufficient (5,156 ft), and the "dual tandem wheel load capacity 
is 300,000 lbs. gross load weight, more than sufficient for the C-130" 
(Castenada, 1981), but the dual wheel capacity (190,000 lbs.) is insuffi- 
cient for C-141 aircraft. Castenada (1981) anticipates "that large fire 
suppression apparatus would need to be moved from Oakland Airport, for 
example, to accomodate the emergency activities at Hayward involving 
large aircraft." "Your office inquired about liquefaction at the Hayward 
Airport and your assessment appears correct. However, [we] have since 
become aware that the enclosed channel of Sulphur Creek extends under the 
main runways (roughly east-west across the north-westerly end of the run- 
ways) and any failure of that structure may cause isolation of the com- 
plete southwest-northeast runway" (Lanferman and Danehy, 1981). Hayward 
Municipal Airport should not be relied upon to provide air-transportation 
access into the area unless suitability is established by further work. 
According to Algermissen and others (1972, p. 169), the runway is 
expected to remain in operation, or become operational again in hours. 

A8 Buchanan Field Contra Costa 

Open for limited use (C-130 aircraft or smaller) . 

The facility is not built upon Bay fill (Nichols and Wright, 1971). Liq- 
uefaction potential is not high (Perkins and others, 1981). Buchanan 



-72- 



Field is 23 ft. above sea level and the water table is at 6 ft. There is 
an emergency generator for the tower, but none for night operation of 
runway lights or for fuel pumps (Vance Roskelley, Airport Operations Sup- 
ervisor, oral communication, 1981). Buchanan Field's longest runway is 
5,000 ft. with a maximum weight allowed of 90,000 lb. (dual) and 140,000 
lb. (dual tandem). It can handle DC-9 and C-130 aircraft, but not the 
C-141 aircraft necessary for large-scale emergency operations. It is 
estimated that the field could comfortably handle six (6) C-131 size air- 
craft at a time, parking them on the inactive major runway and possibly 
as many as twelve (12) in a cramped situation, or the same number of 
large turbine helicopters with similar parking arrangements. Air Naviga- 
tional Aides - The F.A.A. dictates that, in an emergency situation, Field 
Sector Maintenance Personnel are first to make certain the microwave link 
repeater stations (off the airport) are functioning properly efore 
attending to communications at Buchanan. The Tower does have a backup 
communications system ready should the active system fail. Aircraft Fuel 
- No need to fuel the large aircraft is anticipated because they could 
fuel at the airports on the other end of their flight. Helicopters have 
a shorter range and would need fueling services here. About 3,000 to 
12,000 gallons of jet fuel should be on hand to fuel helicopters, 
although the Martinez Shell Oil Refinery (7 miles distance) usually 
stores some jet fuel and, if need be, the helicopters could refuel at the 
refinery. Airport Lighting - The Control Tower has an auxiliary genera- 
tor for communications only (Walford and Kermit, 1981). An auxiliary 200 
kw power generator is needed for runway and taxiway lighting (44 kw) and 
to power the Terminal Building (156 kw) , to enable its use as a coordina- 
tion and relief center. Also needed are smaller portable generators with 
lighting to illuminate the aircraft loading and unloading areas. Roadway 
Access to Field - "At the beginning of a 3 or 4 day weekend, the vehicu- 
lar traffic on Interstate 680 is bumper-to-bumper, stop and go. For that 
reason, I personally do not believe that ground traffic to and from this 
airport will be possible for several hours. (Panic - people concerned 
for relatives, etc.) The main access to the Airport is John Glenn Drive 
off of Concord Avenue on the south side of the Airport (normally moder- 
ately heavy traffic except at commute times when it is stop and go) . A 
new access soon to be available will be from Highway 4 to Solano Way to 
Highway 4 frontage road to Marsh Drive onto the west side of the Airport. 
There is also presently an off ramp southbound from Interstate 680 at 
Pacheco to Contra Costa Boulevard to Center Street onto the west side of 
the Airport..." (Walford and Kermit, 1981). According to Algermissen and 
others (1972, p. 169), the runways are expected to remain in operation, 
or become operational again in hours. 

A9 Travis Air Force Base Solano 

Open . 

The facility is not built upon material with high liquefaction potential 
(Perkins and others, 1981). The area is not underlain by Bay mud and it 
is not subject to liquefaction (Sedway/Cook, 1977, p. 4a). The chances 
for Travis AFB surviving the earthquake in a fully operational condition 
are excellent. It should be seriously considered as the principal stag- 
ing area for the earliest assistance from Federal and State government. 



-73- 



A10 McClellan AFB 
Open > 
Outside the area of intense shaking, 



Sacramento 



All Mather AFB 
Open . 
Outside the area of intense shaking. 



Sacramento 



A12 Sacramento Metropolitan Airport 
Open . 
Outside the area of intense shaking, 



Sacramento 



A13 Stockton Airport 
Open . 
Outside the area of intense shaking. 



San Joaquin 



-74- 



EA RTHQUAKE PLANNING SCENARIO: RA IL ROADS 
Map 1-RM 

General Pattern 

Rail facilities along each of the principal rail corridors leading to the 
San Francisco Bay area are subject to major damage and resulting route closure. 
Therefore, for planning purposes, rail transport to and from the Bay area is 
assumed to be unavailable for at least the initial 72-hour post-earthquake 
period. Rail facilities serving the urban areas around the Bay are also high- 
ly exposed to damage, and while some segments of these lines could be opera- 
tional, their probable utility would be minimal. Facilities of the Bay Area 
Rapid Transit System (BART) will be damaged or will require inspection for 
damage to an extent that will render the system totally inoperative during the 
initial 72-hour post-earthquake period. 

Description 

Because track alignments must be precise and the track clear of debris, 
it is expected that those routes experiencing ground failure would not be 
operable within the first 72 hours after the earthquake. In San Francisco the 
Southern Pacific Commuter Line and the Municipal Railway will be out of opera- 
tion. In Oakland, the AMTRAK Station will be closed. All intra-urban travel 
by rail will be halted. 

For emergency response , railroad access to the San Francisco Bay area 
from outside the affected area is of paramount concern. Emergency planning 



-75- 



for rail transport of relief equipment and supplies will involve location of 
suitable terminals just outside the areas where the major rail lines are 
interrupted. 

From the south, rail access will be cut where it was in the 1906 earth- 
quake — at the Pajaro River bridge east of Watsonville. Consequently, rail 
traffic from the Los Angeles region would have to be routed through the San 
Joaquin Valley. From the San Joaquin Valley, the two major rail corridors 
will be closed in Niles Canyon east of Fremont and near Port Chicago in north- 
ern Contra Costa County. The remaining major rail corridor from the north and 
east will be temporarily closed by ground failure in the crossing of Suisun 
Marsh southwest of Fairfield. The assumed rapid repair of this main line 
would allow for transport of heavy equipment and supplies by rail to suitable 
docking facilities at Benicia where barges could be loaded for continued 
transport to the heavily damaged area around the Bay. Marine facilities at 
Vallejo could also be accessible to the railroad via the line (which should 
remain open) from Fairfield through Jameson Canyon to Vallejo. 

The rail closure near Port Chicago suggests that the Naval Weapons 

Station might be considered as a convenient terminal for some rail transported 

material. Similarly, the closure in Niles Canyon suggests the same possible 
use for Camp Parks. 

The most widespread damage to railroads will occur at those locations of 
structurally poor ground where the roadbed will be seriously disrupted by 
ground movement. These types of failures can generally be rapidly repaired, 
however, given the equipment and personnel that the railroads maintain for 
their normal maintenance operations. 



-76- 



According to Algermissen and others (1973), railway bridges generally do 
not suffer serious damage except in areas subject to ground failure or surface 
fault rupture. Bridge damage, when it does occur, however, generally involves 
a lengthy repair time. Significant settlement of approach fills require re- 
pair before bridge structures can be used. Railroad tunnels experience severe 
damage in areas affected by permanent ground movements due to landslides or 
surface fault rupture, but rarely suffer internal damage from ground shaking. 

Rail facilities are also highly vulnerable to closure by collapse or 
major damage to the many freeway overcrossings and other grade separation 
structures that have been constructed during the past 30 years. 



BART 



The Bay Area Rapid Transit (BART) system is designed to withstand a 
1906-type earthquake and it has "other built-in features that are helpful in 
reducing damage from an earthquake, such as a very heavy car base, two derail 
bars per car mounted diagonally to instantly cause full braking of the 
train... as soon as a train wheel leaves the rail" (LNG Task Force, 1980, 
p. 111-19) . The scenario event will immediately trip the BART strong motion 
detector in Daly City. Unfortunately, this will not, in itself, slow the 
trains. Instead, it will send a signal to central control which will then 
communicate with train operators to slow the trains (Snyder, 1981). If elec- 
trical power is available, the trains will then proceed slowly to the next 
station where they will await determination of damage. The magnitude of its 
power requirements make the development of an emergency generating system for 



-77- 



BART operation impractical, although there is sufficient emergency generating 
capacity to maintain computer control for a few hours. 

People stranded in subways, tunnels, or in the TransBay tube can leave on 
foot. The TransBay tube can be cleared of trains with the use of gasoline or 
diesel-powered "Hi Rail" vehicles, thus opening a route between San Francisco 
and the East Bay. While the BART system has been designed to withstand a 
M 8.3 earthquake on the San Andreas fault without incurring irreparable struc- 
tural damage, it would be unrealistic to expect no damage. After passenger 
evacuation, it would undoubtedly be shut down for an indefinite period while 
damage was assessed and repairs were made. Portions of the system could pre- 
sumably be available for use by the authorities, either with PG&E power or 
using Hi Rail equipment. However, it would be of very limited use compared to 
a railroad, for BART's structures and clearances are not adequate for heavy or 
bulky equipment (Snyder, 1981). Thus, BART should not be relied upon for 
emergency transport in the period immediately following the earthquake. 



Planning Insights 

Rail facilities within the urban areas surrounding the Bay will be non- 
operational and, accordingly, if rail transport is essential to recovery 
efforts, consideration must be given to selection of appropriate rail termi- 
nals where material can be off-loaded for truck, airborne, or barge trans- 
port. Railheads at Benicia and Vallejo may be most critical for movement of 
heavy equipment by barge to heavily damaged areas in Marin County and the San 
Francisco peninsula. Integrated planning needs to be undertaken for air, 
rail, highway, and marine transports. 



-78- 



Recommended Further Work 

Consideration should be given to the possibility of establishing tempor- 
ary terminals following the earthquake where serviceable tracks come into the 
Concord and Livermore Valley areas for off-loading of major supplies and 
equipment. The railheads of Benicia and Vallejo should be examined to deter- 
mine their adequacy for transport of heavy equipment from rail to barge. 

Evaluation is needed of the relative vulnerabilities of the routes that 
give access to the Bay area via northern Contra Costa County. A detailed 
engineering and geologic examination of these routes might reveal that rail 
transport to a closer-in staging area near Richmond (that might also permit 
tratisfer of materials to barges) might be possible. 



RAILROADS 



MAP NOTATIONS 



(See Map 1-RM) 



NO. 



FACILITY 



COUNTY 



Rl BART TransBay Tube 

Closed to normal operations for over 72 hours. 



San Francisco/Alameda 



Although the tube will not rupture, the system will be temporarily with- 
out power. Passengers will be able to walk out of the tube on foot. Hi 
Rail vehicles are available to pull the trains out the east end, but this 
could take up to 24 hours. After the trains are cleared, the Hi Rail 
vehicles would be able to traverse the Bay via the tube, but, as mention- 
ed, they do not have substantial loading capacity, either for passengers 
or supplies. Soil conditions at the east end of the tunnel are similar 
to that at the east approach to the Bay Bridge, which is expected to fail 



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(CDOT, 1981). Both ends of the tube have flexible joints for coping with 
differential movement (BART exhibit, MacArthur Station, 1982). 

R2 BART Subway-SF San Francisco 

Closed . 

The subway will not be damaged extensively, but the system will be shut 
down indefinitely. 

R3 BART Subway-Oakland Alameda 

Closed . 

The subway will not be seriously damaged, but the system will be shut 
down indefinitely. 

R4 BART Elevated Sections 

Closed 

The elevated sections are designed to withstand the shaking effects of a 
M 8.3 earthquake on the San Andreas fault. It is highly probable, how- 
ever, that throughout the system at least a few elevated spans will fail 
and result in closure. 



R5 BART Berkeley Hills Tunnel Alameda 

Open . 

The tunnel section will not be damaged providing there is no sympathetic 

movement on the Hayward fault, which traverses the west end (J. Burns, 

oral communication, 1981) and currently exhibits fault creep (LNG Task 
Force, 1980, p. 111-18) . 

R6 Southern Pacif ic-Suisun Marsh Solano 

Closed for up to 36 hours . 

The tracks were disrupted here during the 1906 event due to liquefaction 
and ground settlement of up to 11 feet (Youd and Hoose, 1978). 

R7 Oakland Army Terminal Switchyard Alameda 

Closed . 

R8 Oakland Naval Supply Center Switchyard Alameda 

Closed . 

R9 SP South Bay Crossing between Fremont and Alameda/San Mateo 

Redwood City 
Closed. 



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RIO SP Commuter Station San Francisco 

Closed . 

Rll Southern Pacific Commuter Line San Mateo 

Closed . 

R12 Western Pacific and Southern Pacific Alameda 

Closed for over 72 hours . 

Sunol is the western-most access to the Bay area along this route. The 
tracks will be closed due to slides and bridge failures similar to those 
involving the highway through Niles Canyon (CDOT, 1981). 

R13 SP and A T & SF Contra Costa 

Closed for up to 36 hours . 

The westernmost access to the Bay area will be disrupted at this point 
along these two lines east of Martinez. 

R14 AMTRAK Passenger Station Alameda 

Closed . 
Station closed due to track disruption. 

R15 Western Pacific near San Jose State Santa Clara 

Closed . 

Northernmost access to lines in the East Bay disrupted at Coyote Creek 
overcrossing south of San Jose State University. 

R16 Mountain View RR Overhead Santa Clara 

Closed . 

Northernmost access to San Francisco on the peninsula disrupted by the 
failure of the Mountain View railroad overhead which is "substandard" 
(Eggleston, 1980). 

R17 Northwestern Pacific Sonoma 

Closed . 

Southernmost access to the Bay Area cut off by track disruption along the 
Petaluma River. 

R18 San Francisco Municipal Railway San Francisco 

Closed . 
Closed by debris and lack of electrical power. 

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R19 Northwestern Pacific at Schellville 
Closed . 
Closed by rail disruption between Schellville and San Rafael. 



Sonoma 



R20 Southern Pacific 
Closed . 
Closed between Napa Junction and Schellville. 



Napa/Sonoma 



R21 Southern Pacific to Vallejo 
Open. 



Solano/Napa 



In wet weather, landslides may cause minor disruption of tracks in 
Jameson Canyon between Cordelia and Napa Valley, but otherwise the route 
to Mare Island Strait will be accessible. 



R22 SP spur to Camp Parks (near Pleasanton) 
Open . 
Most likely westernmost terminal on this line. 



Alameda 



R23 Pajaro River Bridge 
Closed. 



San Benito 



Northernmost access to the Bay Area via the coastal route from the south 
will be interrupted due to offset along the San Andreas fault as in 1906. 
"Its failure is anticipated in the event of an 8.3 magnitude shock" 
(Algermisson and others, 1972, p. 156). 



R24 Naval Weapons Station Terminal 
Open . 
Most likely westernmost terminal on this line. 



Contra Costa 



R25 Port Chicago Terminal 
Closed . 
Closed due to ground failure and disruption of rails. 



Contra Costa 



R26 SP and WP between San Jose and Oakland 
Closed . 
Closed for repairs along the southern section. 



Alameda 



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R27 SP between San Jose and San Leandro Alameda 

Closed . 
Closed due to ground failure and track disruption. 

R28 Mare Island Bridge Napa 

Closed . 
Closed due to failure of bridge. 

R29 Mare Island Strait Terminal Napa 

Open . 

Southernmost access to the Bay Area along this line. Open and usable for 
marine transport, although access depends upon assumed minor problems 
along route through Jameson Canyon (R21) . 



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THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIO 

For a Magnitude 8 3 Eorthquake on the Son Andreas Foult in 

the Son Francisco Bay Area 

RAILROADS AND MARINE FACILITIES 




EARTHQUAKE PLANNING SCENARIO; MARINE FACILITIES 

Map 1-RM 



General Pattern 

The majority of the docks around the Bay are supported on piles and these 
should not be significantly damaged. Operations at the container terminals, 
however, which are generally constructed on fill, will be seriously impaired. 
Disruption of rail facilities, impaired highway access, toppling of cranes, 
pipeline ruptures, and similar problems will be controlling factors affecting 
the use of the various port facilities. 

The use of barges to transport heavy equipment and supplies to heavily 
damaged areas will be dependent on the integrity of docks. The major bayside 
facilities at San Francisco, Oakland, Richardson Bay, Richmond, and the 
Carquinez Straits should be accessible for tug and barge operations. South of 
Hunters Point and San Leandro, all facilities would be inaccessible to larger 
vessels including tug and barge traffic. 



Description 

According to Algermissen and others (1972, p. 170), during the 1906 earth- 
quake "performance of the pile-supported docks along San Francisco's water- 
front was excellent, although the soil in some fills nearby settled in terms 
of feet." Quay wall facilities, however, have not performed as well. (A quay 



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wall is a waterfront wall with an earthen fill behind. Failures of quay walls 
have generally been attributed to liquefaction of the soils behind the quay 
walls, forcing the walls outward). 

Most of the docks in the Bay area are pile supported and, overall, marine 
facilities are not expected to be greatly affected insofar as the pile-sup- 
ported docks are concerned. However, some cranes will be thrown off their 
rails. Pipelines from storage tanks to docks will be ruptured where they 
cross areas of structurally poor ground in the vicinity of the docks. Res- 
tricted access to docks due to damage to freeways and nearby surface streets 
will be more common than significant damage to the pile-supported docks. 

Bayside port facilities at San Francisco, Oakland, Richardson Bay, Rich- 
mond, and Carquinez Straits will be generally accessible to tug and barge 
traffic. Marine facilities south of Hunters Point on the peninsula and San 
Leandro in the East Bay will, however, be inaccessible to both tug and barge 
movement. 

Algermissen and others (1972) concluded that "The overall effect is not 
expected to impair the efficiency of the study area port facilities by more 

than 15%." 

The following comments were developed for this evaluation by the Marine 
Transport Committee of the Governor's Emergency Task Force on Earthquake 
Preparedness: 



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Regardless of the specific area or time of day, the estimates set forth in 
this section should be valid due to the basic nature of maritime activity. It 
is expected that damage to most dry cargo port facilities and marinas should 
be less than in previous severe quakes due to modern building techniques and 
facility spacing. However, the failure of quay walls and lateral displacement 
at container terminals could be expected to be severe so that operations would 
be drastically curtailed. Inasmuch as these facilities are constructed on 
filled land, cranes could topple, tracks could become misaligned, and automa- 
tic shore-side container storage and distribution cells could be warped. 

Most vessel cargo transfer operations are self-contained so that, except 
for container ships without cranes, cargo operations could be continued after 
a major earthquake to the limit of shore-side support. The controlling fac- 
tors will be restricted road access, pipeline breaks, and fill land failures 
in the vicinity of piers and terminals. 

At liquid handling facilities no significant damage to either vessels or 
piers is expected. However, shore pipeline failures could be expected, and 
even if no failure occurred, cargo operations will cease until all systems 
have been thoroughly checked. 

Generally speaking, dry bulk cargo and container operations could be ex- 
pected to come to a halt due to access problems and shifts in land fill 
areas. Over a short period, or even a moderately long period, this shutdown 
would have no significant effect on life-line functions in an earthquake 
impacted area due to the indirect consumer nature of modern inbound cargos. 



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Vessels destined for an impacted port area would be diverted at sea to alter- 
nate port facilities or delayed in arrival to an impacted area. 

Small craft facilities may suffer minor damage through ruptured pipelines 
and slides under piers from adjacent fill land. The most significant impair- 
ment would probably be closure of waterways in some areas. In the South San 
Francisco Bay and the southern half of the East Bay areas, dredged channels 
could be expected to shift so the small craft in the vicinity of Redwood City 
and south, and craft in the Alameda-San Leandro areas would be confronted with 
blocked channels. The North Bay and nearby Delta areas are expected to be 
accessible by small craft. 



Planning Insights 

The use of tugs and barges to transport heavy equipment and supplies to 
the San Francisco and Marin peninsulas appears to be a viable emergency re- 
sponse procedure. Assuming that most of the docks in the heavily damaged 
areas will be usable, availability of emergency power and off-loading capabi- 
lities will be requisite. Use of barge transport will necessitate coordinated 
planning for loading of needed material at a docks ide facility adjacent to a 
marshalling depot and/or railhead with corresponding loading capabilities. 

Transport of emergency personnel and equipment into these same heavily 
damaged areas and evacuation of the injured will be a vital function of the 
numerous Bay ferries. Planning should consider the most feasible terminals 



-88- 



(on both ends) in order to complete these missions. Again, coordination with 
other ground transport capabilities will be required in order to effect effi- 
cient transfers. 

The utilization of privately-owned vessels to augment this supply and 
evacuation effort is appropriate. Practical education, planning, and training 
programs to implement this participation should be initiated. 



Recommended Further Work 

The various roles that marine transport can assume in the emergency 
response efforts and the extent of marine transport resources should be deter- 
mined. The port facilities in the areas of expected heavy casualties/damage 
should be assessed, and locations with suitable land-access and loading capa- 
bilities, that are most likely to be available for post-earthquake access to 
marine transport, should be selected. Port facilities outside the heavily 
damaged areas should be coordinated with ground transport to identify the most 
efficient means of transporting the injured, materiel, etc. 

The capabilities of private vessels and the potential roles of their oper- 
ators should be determined. Appropriate training programs should be estab- 
lished to ensure the emergency-response effectiveness of this resource. 



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MARINE FACILITIES 

Map Notations 

(See Map 1-RM.) 

NO. FACILITY COUNTY 

Ml San Francisco Waterfront San Francisco 

Along the San Francisco waterfront there will be numerous failures of 
quay walls, disruption of waterfront rail facilities, derailment of 
cranes and railroad cars, ruptured pipelines, etc. Docks are generally 
pile-supported, however, and most will be accessible for emergency 
response operations. Access to the waterfront will be impaired by debris 
and major damage along many approach streets. 

M2 Oakland Inner Harbor-Alameda Alameda 

Port facilities in the Oakland Inner Harbor and Alameda will experience 
moderate damage of the same nature as enumerated in note Ml above. 
Disruption of both rail and road access to Alameda and its port facili- 
ties will be a controlling factor in resumption of operations. 

M3 Oakland Outer/Middle Harbors Alameda 

Operations at the large cargo terminals located in the Oakland Outer and 
Middle Harbor areas will be significantly disrupted. Built on fill of 
questionable merit, these areas will experience ground failures causing 
considerable disruption to the piers, the extensive rail systems, cranes, 
and warehouse facilities. Rail access to the area is assumed to be 
unavailable for at least 72 hours and the limited vehicular access will 
be further restricted by heavy damage to the nearby freeway system. 

M4 Richmond Contra Costa 

Port facilities at Richmond will sustain localized ground failures dis- 
rupting rail and street access. Damage to oil pipeline and storage 
facilities near the harbor poses a threat of contamination and fire. 

M5 Alameda-San Leandro Alameda 

Small craft facilities in the San Leandro and Alameda areas will be 
closed by blocked channels. 



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M6 South Bay San Mateo-Santa Clara 

All marine facilities at Redwood Creek, Palo Alto, and Alviso Channel 
will be inoperable and inaccessible. 



M7 Petaluma River Sonoma 

The Petaluma River will be blocked. 

M8 Benicia-Vallejo Solano 

Damage to marine facilities and appurtenant rail connections at Benicia 
and Vallejo will be minor. Allowing 36 hours to accomplish necessary 
repairs to the main line tracks across Suisun Marsh (see note R6) and 
minor repairs due to landslides in Jameson Canyon (see note R21) rail 
service to these two Bayside facilities will be available. 



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EARTHQUAKE PLANNING SCENARIO: COMMUNICATIONS 

Map 1-C 



The following discussion of communication systems was prepared by the 
Communications Advisory Committee of the Governor's Emergency Task Force on 
Earthquake Preparedness. James Cotter is principally responsible for develop- 
ment of this analysis. 



General Pattern 

Telephone communications will be adversely affected due to overloading 
resulting from post-earthquake calls within the area and from the outside. 
This situation will be further complicated by physical damage to equipment due 
to ground shaking, loss of service due to loss of electrical power and sub- 
sequent failure of some auxiliary power sources. 

Not all of the systems in the region are set up to process emergency calls 
automatically on previously established priority bases. Thus, overloading of 
equipment still in service could be very significant. 

Telecommunications systems are composed of many subsystems, each intercon- 
nected and interdependent. A radio network, for example, may use a combina- 
tion of telephone lines, microwave circuits, satellite interfaces, underground 
and overhead cables, and secondary radio paths. The failure of one link in 
this electronic "chain" can effectively disable a large portion of the 



-93- 



system. The post-earthquake communications scenario has been treated as a 
matrix of events that would reduce the effectiveness of systems rather than 
completely destroy them. It is also assumed that portions of many systems 
could be repaired to a limited extent by resourceful operators. Criteria such 
as geographical coverage, the number of system elements, and functional inte- 
gration were considered in estimating the post-earthquake effectiveness of a 
particular system. With the maximum capacity of any system represented as 
100%, most systems operate at approximately 85% because of ongoing mainten- 
ance. The effects of the scenario earthquake must be applied to this ratio to 
determine the degree to which the overall effectiveness is reduced. "Effec- 
tiveness" is defined as the ability of a system to perform to its design 
limits and provide the intended service. 



Description 

The communications scenario is described in subsections, each of which 
treats one of the following generic systems: telephone, radio, microwave, 
satellite, data, and commercial broadcast. 



Telephone Systems 
Map No. 1-C 



Telephone systems are mutually interdependent because of a vast, complex, 
interconnected network, yet they are also self-supporting on a local basis. 



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One service provided by the telephone companies is intraexchange traffic, 
i.e., calls between telephones within the area served by a single central 
office or "exchange." Another is interexchange service where calls are 
switched between two central offices within a region. There is third service, 
similar to interexchange, where calls are routed to a long-distance facility. 
Each of these services can be provided by a variety of system configurations. 

The telephone companies have installation standards that minimize earth- 
quake damage. They also have emergency mobilization plans and have exercised 
these plans effectively. Nonetheless, there has not been a disaster in modern 
times of the magnitude here addressed. It is therefore quite difficult to 
forecast the detailed effects of a major earthquake on the telephone systems. 
There are, however, a number of outcomes that can be anticipated: hardware 
damage such as underground cable failure in areas of liquefaction, damage to 
surface cable carriers, system-call saturation during post-earthquake 
recovery, and repair-access problems. 

Our evaluation of system performance takes into account the likelihood of 
any or all of these events occurring and subjectively applies this evaluation 
to an effectiveness scale, as shown on Map 1-C. The effectiveness scale 
essentially is an attempt to quantify the ability of public safety agencies to 
conduct recovery efforts by using the telephone system. It is not directly 
applicable to the general performance of the system nor to the public's 
ability to use the system. 

The effectiveness scale has then been applied to a three-day time frame. 
Four patterns of effectiveness over time were distinguished and used as the 



-95- 



basis for zoning the study area (Zones A, B, C, and D on Map 1-C) . Zone A 
will fair best and Zone D the worst. The definitions of these zones are based 
upon a number of factors: past telephone performance in disaster situations, 
casualty projections, population density and demography, post-earthquake 
transportation evaluations, the probable performance of commercial power fac- 
ilities, and any known site-specific technical considerations. No attempt has 
been made to separately evaluate each of several hundred telephone facilities. 

Some basic assumptions have been made: (1) the shaking intensities used 
in this scenario were projected by the CDMG as shown on Map 1-S; (2) areas 
experiencing a shaking intensity of 8 (R-F) or greater will have significant 
hardware damage although such damage would be fairly localized and not on a 
large regional scale; (3) some underground cables will be damaged by ground 
failure, but not in sufficient number to preclude switching alternatives; (4) 
most predesignated public safety circuits will receive priority restoration; 
(5) most telephone company backup power provisions will be functional; (6) the 
long distance network, although difficult to access, will remain generically 
stable; (7) interexchange facilities will be difficult to access, but would 
remain essentially intact; (8) shortly after the event, numerous relatively 
simple failures will occur that, coupled with intense call saturation, will 
effectively disable the telephone networks for approximately 6 hours; and (9) 
for planning purposes, the event will be considered to occur after normal 
business hours. 



-96- 



Specific Vulnerabilities 

The most vulnerable aspects of telephone systems are the computers used to 
switch message traffic. All are environmentally sensitive and may be mounted 
on false floors. The performance of these computers is not easily associated 
with a time frame because of the long-term effect of environmental control 
failure. Call saturation, resulting in local station and all- trunks busy, is 
the most obvious system access problem that can be predicted. Most telephone 
systems presently are working at or near capacity for normal traffic; the sys- 
tems will be saturated easily by the sudden activity following an earthquake. 
Most exchanges, however, have the capability through the switching computers 
to control system load by limiting access to only predesignated circuits. 
Another potential problem is emergency power. While the telephone systems 
work mostly on battery power, with propane or gasoline backup generators to 
provide charging, the generators depend upon batteries for starting and fuel 
lines and tanks for continued operation. If emergency power does fail, system 
performance on batteries will degrade at a significant rate. 

Assuming the earthquake will occur outside normal business hours, a number 
of staffing dimensions must be considered when evaluating telephone system 
performance in the scenario. The first concern of telephone company employees 
will be assessment of their own immediate condition; second, they will be con- 
cerned about their families and friends. A small percentage of staff will 
leave their jobs to ameliorate the effects of the disaster in their personal 
lives. Some of the employees will suffer casualties and will be confronted 
with mobility problems on streets and highways. The repair-vehicle fleets 
will probably be generally inaccessible to staff for several hours and, in 



-97- 



some cases, will probably be Immobilized by facility failure. In systems that 
must revert to operator intercept, where all dialed calls go to an operator, 
fatigue would curtail effectiveness. The same fatigue will apply to central 
office personnel. Further, the telephone companies will probably be without 
upper-echelon management and supervisory personnel during the first hours 
following an earthquake; the transportation situation may be magnified because 
these persons often live further from their office than journeymen. Another 
portion of staff will be unavailable because of normal vacation and illness. 

It is likely that telephone company mobilization plans will be difficult 
to implement because of the exercise of other priorities by local and State 
government as well as limited transportation. The thousands of repair parts 
and materials needed for recovery may also be difficult to obtain. 

In summary, the effects of a major earthquake on telephone systems will be 
dynamic and dependent upon a multitude of events rather than upon any single 
factor. The overall evaluation, thus, is highly subjective and must be con- 
sidered only as a public safety planning document. 



Post Earthquake Telephone Systems Effectiveness 

San Francisco Bay area: The volume of calls that would follow the 
scenario earthquake if it occurred after normal business hours would not be as 
haavy and paralyzing to the telephone system in San Francisco, with its high 
business concentration, as it would be during that time period in more heavily 
residential areas. But, although the system in San Francisco has line access 



-98- 



control, it is more isolated systemically than the Los Angeles metropolitan 
area, for example, and is very dependent upon a few telecommunications arter- 
ies. Key system facilities are located near the San Andreas fault in areas 
projected to experience intense shaking. It is likely that the telephone 
systems in and to the south of San Francisco will have systemic failures not 
readily compensated by alternative traffic routing. It is also probable that 
the recovery effort will be delayed because many company employees live out- 
side the city limits and important transportation routes will be impassable. 

There is a very good system in San Francisco for identifying important 
public safety telephone circuits. These dedicated lines should be minimally 
disrupted. The effectiveness rating, however, is quite low because local 
agencies will presumably require a great amount of outside assistance; the 
ability of the telephone system to meet these needs will be limited. 

In Marin County, telephone system vulnerability was evidenced by the 1982 
storms. The geography and demography is such that alternate routing is limit- 
ed. Key central offices are located in areas expected to suffer severe shak- 
ing and ground failure. Many access routes will be impassable. This area is 
particularly susceptible to underground cable and surface cable carrier fail- 
ure. Line load control is available but would not alleviate other systemic 
problems. 

Although the Oakland/East Bay area has a substantial number of telephone 
facilities located in intense shaking and high probability of ground failure, 
access to accomplish repairs should not be a major problem. Further, there 
are several switching options. Systems in this region have line access con- 
trol and predesignated public safety circuits. 



-99- 



Systems in the San Jose/South Bay area will experience severe shaking in- 
tensities and have extensive areas of potential ground failure. Despite this, 
repair staff should be in reasonable proximity to their offices with fewer 
access problems than adjacent areas. The telephone systems will be saturated 
but have designated circuits and line-load controls. Because of shaking pat- 
terns corresponding with key facility locations, the South Bay area is likely 
to experience complete localized telephone failures on a block-by-block basis. 



Radio Systems 



Radio systems will generally operate at 40% effectiveness for the first 12 
hours after the earthquake, increase to 50% for the second 12 hours, then 
begin a slow decline to approximately 40% within 36 hours. The long-term 
implications are that individual systems gradually will become less useful to 
the overall recovery effort when supplanted by systems relocated from outside 
the disaster area. It is unlikely that public safety radio systems would be- 
come saturated with non-critical communications from mobile units; it is clear, 
however, that radio traffic densities on redundant (non-emergency designated) 
channels would increase, particularly when remote base station and repeater 
failures would tend to limit the number of redundant channels available. 
Nonetheless, after 12 hours, at which time the number of operable units will 
have declined (with exhaustion of emergency power fuel) and recovery efforts 
will have restored some order, the radio traffic density problem will ease. 



-100- 



For each of the various components of a radio system, we anticipate 
specific effects under the scenario. These effects are described in the 
following component discussions: 



Radio Control Consoles 

Radio control consoles generally fall into three categories: self-contain- 
ed tabletop base stations, tabletop control consoles for remote base stations, 
and full-size consoles using electronic circuitry (often very sophisticated) 
to control remote base stations. Both tabletop models are vulnerable to 
earthquake damage because they are rarely secured. While the self contained 
station is more likely to remain functional than other types (since it doesn't 
rely on remote equipment) , it is often not supplied with emergency backup 
power. System designs using control stations normally have such backup power 
provisions. Control consoles rely either upon telephone or microwave circuits 
to access remote equipment. We do not anticipate continued microwave opera- 
tion and cannot recommend telephone lines as an alternative, though such dedi- 
cated control circuits are more likely to remain functional than conventional 
telephone service. Sophisticated consoles are better protected against physi- 
cal damage and normally have emergency power available, but they rely upon 
telephone and microwave circuits and have an added problem of repair complex- 
ity. If a key component of a large console fails, many radio subsystems would 
be fragmented, placing the burden of communications on outlying stations more 
vulnerable to earthquake damage. Further, software-based consoles would 
probably face additional complications within 12 hours. We estimate that 
self-contained tabletop base stations would be 40% effective, tabletop control 
consoles 55% effective, and large consoles 50% effective. 



-101- 



Base Stations 

Radio base stations are often located on the roof of the same building 
housing the control console. In such cases, the condition of the building 
would determine post-earthquake performance. Even if cabling between the two 
units was to fail, base stations can be operated on-site via a microphone pro- 
vided within the equipment cabinet. Dispatchers, however, are not normally 
aware of this and even more rarely have the key needed to gain access to the 
microphone. Remote base stations, located in a different building or in a 
mountain-top radio vault are subject to potential structural damage. Stations 
atop buildings are probably less vulnerable to wiring and component malfunc- 
tions than other installations but share the threat of telephone circuit 
interruption. We estimate that effectiveness will be 70% for local base 
station installations and 55% for remote stations, declining after 12 hours as 
emergency-power fuel supplies become exhausted. 



Repeaters (mobile relays) 

Repeaters are not dependent upon control circuits and are normally provid- 
ed with backup emergency power. Located atop mountains, they are vulnerable 
to structural, electric, and other internal damage from heat buildup. Depend- 
ing upon the proximity of the fault source, they are more likely to experience 
technical problems than base stations. We estimate that repeaters will be 60% 
effective, declining as emergency power supplies are exhausted and technical 
problems develop, becoming 40% effective after 24 hours. 



-102- 



Antennas 



We do not believe that antennas will fail on a large scale. Antennas and 
related structures should remain 70% effective. 



Hand-held and Portable Two-way Radios 

It is probable that hand-held radios will be valuable to field units dur- 
ing the first 12 hours after a major earthquake, particularly in a system that 
does not use repeaters. In any case, there are problems with charging and 
distributing batteries. We do not consider this kind of portable equipment to 
be of any significant benefit to the overall recovery effort after 12 hours 
per battery that is available to each unit; that is, a unit equipped with one 
fully-charged backup battery would be operational for 24 hours total. 



Mobile (Vehicular) Radios 

Assuming that gasoline supplies will be scarce and that transportation 
systems would be disrupted, the value of mobile radios would coincide with 
their distribution at the time of the disaster. We estimate that, function- 
ally, higher-powered mobile radios would be 75% effective for the first 
12 hours, declining thereafter because of fuel and battery problems. At the 
same time, the mobile radio system as a whole would doubtlessly be compromised 
because of the distribution of the units. It is more realistic to consider 
mobile radios approximately 60% effective initially, declining thereafter. 



■103- 



This estimate is for public agencies; should an earthquake occur after working 
hours, the effect on commercial systems will be more severe. 



HAM and Other Amateur Radio 

Amateur radio stations are subject to the hazards outlined earlier. A 
particularly vulnerable point is emergency power; most home base stations do 
not have backup facilities. Nonetheless, there is an extensive vehicular 
radio and repeater system in the amateur radio service. Much of the first 
post-disaster intelligence would come from this private sector resource and, 
in some cases, radio amateurs may be the only means of reaching the outside 
world. The amateur radio service should remain more than 50% effective be- 
cause of pre-organization and the long distance capabilities of the equipment. 



Citizens' Band Radio 

We do not believe that CB radios will have an appreciable effectiveness in 
the public agency recovery effort, although there would be some post-disaster 
intelligence value. The units are too low-powered and are susceptible to fre- 
quency saturation. It is possible that CB "zones," each zone using a predes- 
ignated channel, could be established within neighborhoods for the self-help 
effort. Being the most accessible two-way communications resource for the 
general public, Citizens' Band would be a significant element in the smaller 
recovery "cells" if users receive prior education and orientation. 



-104- 



Radio Common Carrier (RCC) 

Radio common carriers will be subject to the events noted earlier for 
public agencies. 



Aircraft and Marine Radio Communication 

Either radio service will be at least 80% effective provided that air- 
fields are nominally accessible and there are no severe conditions that would 
significantly disrupt moored maritime resources. While there are many poten- 
tials within either service for providing good quality emergency communica- 
tions, existing land-based systems are completely incompatible. The overall 
effectiveness of marine radio must be equated to prior frequency coordination 
for marine transport systems. The relative importance of these radio services 
would increase as recovery efforts commence. 



Microwave Systems 

Microwave systems have all the vulnerability of other radio systems plus 
additional problems related to narrow frequency tolerances, softwarecontrolled 
switching systems, and sensitive gain (directionability) tolerances. Addi- 
tionally, many systems are not point-to-point but are linked through several 
points. The likelihood of failure in any one link is fairly great; therefore, 
we feel that microwave systems, with the possible exception of telephone 
microwave systems, will not extend beyond the affected disaster regions. Some 



-105- 



circuits may remain operable on a point-to-point basis. It is estimated that 
most microwave systems would be 30% effective or less. 



Satellite Communications 

Remote satellite terminals relying upon telephone or microwave circuits 
will be 40% to 50% effective, similar to radio base stations. Stationproxi- 
mate terminals will have a greater likelihood of survival approximating 70%. 
Because the satellites themselves are impervious to earthquake damage, they 
are one of the most significant resources for supplanted communications 
systems. 



Data Communications 

Communications systems used to support computers will be 40% effective. 
When facilities are not physically damaged, air conditioning and environmental 
control systems failures may gradually reduce effectiveness. 



Commercial Broadcasters 

Some commercial stations generally will be able to provide emergency 
public information to the stricken area. 



-106- 



Medical Services Radio Systems 

The VHF medical services radio frequencies are crowded and poorly coordi- 
nated. UHF repeater systems, while less saturated, are more vulnerable to 
damage and failure. There are insufficient channels dedicated to telemetry; a 
large number of casualties could cause saturation of the channels and make 
them virtually useless. Further, the hospital-to-hospital systems are expect- 
ed to fail. We do not anticipate the continued function of medical radio 
services to an appreciable level of effectiveness. 



General Comments on the Communications Scenario 

The lack of emergency power has been the primary cause of communications 
failure in past disasters. Poor installation practices and inadequate preven- 
tative maintenance of backup power equipment contribute to a high failure 
rate. The presumed scarcity of propane and gasoline after a major earthquake 
will strictly limit the viability of surviving communications sites. 

The availability of repair parts and ability to transport them are other 
factors when considering both shortand long-range implications. We believe 
that supplanted communications systems will be needed as local systems suffer 
earthquake-caused and normal equipment malfunctions for which there are no 
repair parts. 

The current state of technology is such that communications technicians 
have specialized areas of expertise. The tools, test equipment, and repair 



-107- 



parts they use are often suited only for the particular type of equipment a 
particular specialist works with. As a result, one specialist would have dif- 
ficulty repairing equipment that is outside his area of specialization. Most 
radio technicians, for example, are unable to repair microwave equipment, 
military staff are unable to repair some types of public radio equipment, and 
microwave specialists are unable to assist telephone staff. This problem is 
further compounded by the unique characteristics of many systems otherwise 
generically related. Depending on the time the earthquake occurs, the number 
of technical staff available for repair services could range between 20% and 
50% of the total for the first 24 hours. If it occurs between 1600 and 
0600 hours, approximately 20% may be available in the first 24 hours, 40% in 
48 hours, and 70% in 72 hours. If the disaster occurs between 0600 hours and 
1600 hours, some personnel would be disabled, isolated, or occupied with veri- 
fying the status of their families: 50% will be available for the first 24 
hours, 60% in 48 hours, and 70% in 72 hours. The effectiveness of technical 
personnel is severely affected by the availability of transportation. In many 
cases, for example, helicopters would be needed for access to remote sites. 
Technical staff would only be able to support the continued operation of sys- 
tems at a level of post-disaster effectiveness. After approximately one week, 
system performance would begin improving. 

The regulation of communications has necessarily separated users to avoid 
mutual interference. One result of this separation is mutual exclusion. Ex- 
cept in rare circumstances, two adjacent communications systems are physically 
or functionally incompatible. The greatest danger to a post-earthquake recov- 
ery effort is the absence of adequate interface between systems. This applies 
equally to local systems and systems drawn from outside the disaster area. 



•108- 



Planning Insights 

A general communication plan should be developed for use , following the 
earthquake, by appropriate agencies and personnel with emergency-response 
roles. This plan should anticipate the needs of the most vital parties. 

Reliance on emergency telephone communications should be kept at a mini- 
mum. A strategy should be developed for communication to the general public 
which relies upon the capabilities of surviving commercial radio and tele- 
vision stations. 



Recommended Further Work 

An inventory of commercial and amateur broadcasting capabilities should be 
undertaken and the resulting information employed in developing the regional 
emergency communications plan. 

A survey of existing critical communications facilities should be under- 
taken by structural engineers leading to development of improved equipment 
installation standards. 

There is need for a continuing technical examination and overview of 
alternative means of communication with the object of working out regional 
plans for communication between emergency workers and the public at large. 
There is a need for a technical examination of alternative means of 
communication, e.g., satellite. 



-109- 



COMMUNICATIONS 



MAP NOTATIONS 



(See Map 1-C.) 



On Map 1-C, there are no notations for specific sites or facilities. As 
explained on the map, areas are zoned according to the level of telephone sys- 
tem effectiveness expected during the first three days following the earth- 
quake. Four levels of expected effectiveness, ranging from highest to lowest, 
are distinguished. Zone A areas are those expected to have the highest levels 
of post-earthquake effectiveness, and Zone D areas, the lowest. 



-110- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIO: WATER SUPPLY 

AND WASTE DISPOSAL 

Map 1-W 



General Pattern 

Several of the major aqueducts that deliver Imported water to various seg- 
ments of the planning area will sustain damage causing temporary interruptions 
in supply. The numerous major reservoirs in the area provide ample storage to 
meet demands during the time required for repairs. However, impairments to 
water transmission lines, local storage reservoirs, and pumping plants, as 
well as local distribution systems, will affect water availability and pres- 
sure. The absence of electrical power for extended periods will in some areas 
preclude water deliveries where pumping is necessary, even though conveyance 
facilities may be intact. Many areas could be dependent on tanker trucks to 
provide their basic needs. For planning purposes, one major dam (Lower 
Crystal Springs Dam, in San Mateo County) is assumed to incur major damage 
necessitating downstream evacuation procedures. 

Sewage collection systems will sustain widespread damage, particularly in 
the low-lying areas nearer the Bay. The many sewage treatment facilities also 
located in structurally poor ground adjacent to the Bay will be damaged and 
experience electrical power losses resulting in discharge of raw sewage into 
the Bay. 



-Ill- 



Description 

The water supply to the Bay area is provided by several systems. The vul- 
nerability of each of these systems must be appraised holistically. That is, 
the individual component parts of each system — the water source, aqueducts, 
local storage reservoirs (including dams), pumping stations, transmission 
lines, and local distribution lines — each must be viewed in the context of 
the entire system and its performance. Impairment of any one of these major 
elements could seriously compromise the performance of the whole system. For 
emergency planning purposes, it is important to recognize that this domino 
effect makes the system's overall performance more vulnerable than casual 
examination of individual components might suggest. 

Several major aqueducts import water to various parts of the planning area 
and most of these are, to some degree, vulnerable to damage as a result of the 
scenario earthquake. The City of San Francisco and a number of municipal 
utilities in San Mateo, Santa Clara, and Alameda counties receive water 
imported from the Tuolumne River in the western Sierra Nevada via the Hetch 
Hetchy Aqueduct, operated by the City of San Francisco. The South Bay area 
and Livermore Valley has received imported water from the South Bay Aqueduct 
since 1965, and in the mid-1980s Santa Clara County will receive its first 
water deliveries from the U.S. Bureau of Reclamations (U.S.B.R.) San Felipe 
Project (water from San Luis Reservoir via Pacheco Tunnel). Most of the East 
Bay also receives its water from the Sierra Nevada via the East Bay Municipal 
Utility District's Mokelumne Aqueduct. Contra Costa County imports water via 
the Contra Costa Canal from the San Joaquin delta. 



-112- 



In the North Bay, southern Sonoma County is dependent upon the Petaluma 
and Sonoma Aqueducts to deliver water south from the Russian River. Southern 
Solano County receives water via U.S.B.R.'s Putah South Canal, from which 
water is delivered to southern Napa County through facilities of the North Bay 
Aqueduct. Marin County is largely dependent upon locally developed water 
storage facilities. 

Any one, or all, of these larger aqueducts could be ruptured or damaged as 
a result of the scenario earthquake. Significant failures could result in 
flooding, erosion, and other secondary damage that could compound efforts to 
consumate repairs. For planning purposes, it has been assumed that the Hetch 
Hetchy, Mokelumne, Petaluma, and South Bay Aqueducts will sustain some 
damage. Damage to these and certain other critical water facilities are 
described in the notations for Map 1-W. 

While there should be ample water storage in the numerous Bay area reser- 
voirs to satisfy all water demands during the period while aqueduct repairs 
are in progress, the distribution system may be such that deliveries to all 
service areas may not be possible. In the short-term, the loss of electrical 
power will prevent pumping water to many areas at higher elevations and, thus, 
only undamaged gravity systems will be able to provide a continuous water 
supply. This may be most critical on the Marin and San Francisco peninsulas 
where a substantial population resides at higher elevations and where the time 
required to restore electrical power may be most lengthy. 

Of all the aqueduct systems, the Hetch Hetchy Aqueduct is regarded as the 
most critical from the standpoint of a large dependent population and vulner- 
ability to damage. The location of the Hetch Hetchy Aqueducts is shown on 



-113- 



Map 1-W. Damage has been assumed at three general locations where the Aque- 
ducts cross the South Bay. Hetch Hetchy water is stored at San Andreas Lake 
and Crystal Springs Reservoir, both on the San Andreas fault. Water is then 
transmitted through several large pipelines to storage facilities in the City. 

The 1906 earthquake provided an example of the performance of these fac- 
ilities that might be expected from another comparable event (as assumed in 
this scenario) , for most of the present facilities follow the same routes as 
in 1906. 

Algermissen and others (1972, p. 175) conclude that "The Hetch Hetchy 
aqueducts can be reasonably expected to deliver water to the peninsula reser- 
voirs, and these reservoirs can be expected to remain intact. Quick repair- 
able damage is likely where one conduit enters an underwater crossing of San 
Francisco Bay. For planning purposes, half of the aqueduct supply from the 
San Andreas and Crystal Springs reservoirs should be assumed to be out of 
service for a week; however, as in 1906, the storage reservoirs located in San 
Francisco will function." In general, we concur with these NOAA conclusions. 



Water Storage Reservoirs 

Catastrophic failure of a major dam as a result of the scenario earthquake 
is regarded an unlikely. Current design and construction practices, and 
on-going programs of review, modification, or total reconstruction of existing 
dams are intended to ensure that all dams are capable of withstanding the 
Maximum Credible Earthquake (MCE) for the site. For the purposes of emergency 



-114- 



planning, however, it is prudent to consider that one major dam within the 
study area will sustain damage affecting its integrity. For this scenario, it 
has been assumed that Lower Crystal Springs Dam develops significant leakage 
necessitating evacuation of the downstream population. 

Lower Crystal Springs Dam is a 140-foot high concrete gravity dam con- 
structed in 1888. Storage capacity is 54,000 acre-feet. Though the structure 
is located within a few hundred feet of the 1906 surface rupture it survived 
that earthquake without damage. 

Carrying the assumption of leakage of Lower Crystal Springs Dam to the 
extreme, one could postulate the necessity to rapidly and totally drain the 
reservoir. Emergency planners should also consider the ramifications of this 
loss of storage on water operations. 



Distribution System, Including Reservoirs, Pumping Plants and Distribution 
Pipelines. 



It is expected that distribution reservoirs will suffer moderate damage: 
underground excavated type reservoirs, with column- support roofs, could suffer 
extensive roof collapse; for tank-type reservoirs of concrete construction, 
pipeline connections and surface damage to the shell are expected; distribu- 
tion reservoirs of welded or bolted steel construction will suffer little 
damage, but connections will be severed in some cases. The damage to distri- 
bution storage will be significant, primarily at connections, and will likely 
lead to early loss of storage (Finlayson, 1982). 



-115- 



Pumping Plants are generally compact structures and, with the exception of 
related electrical equipment and transformers, will probably not suffer as 
much damage as the reservoirs. Large pumping plants will suffer damage close- 
ly related to the materials in which they were constructed, and damage will be 
primarily related to pipeline rupture and transformer damage. 

Distribution Pipelines vary from 2 inches to 54 inches or more in dia- 
meter. Pipe materials vary from cast iron to welded steel and asbestos cement 
to a variety of plastic materials. The damage to distribution pipelines is 
expected to vary with pipe material, soil type, design installation practices, 
and shaking intensity. It is anticipated that all water systems within the 
region will suffer some damage. Depending upon local conditions, the popula- 
tion impact may be small, or catastrophic. In areas of intense shaking and/or 
ground failure it will not be unusual to find that there are 2 to 4 main 
breaks in every block where cast iron or asbestos cement pipe is used. Where 
such general damage to the water distribution system occurs it will be vital 
to repair water mains at the lowest topographic point first, and work uphill 
so that broken sewers in the same areas do not contaminate still broken water 
lines. The difficulty in determining the extent of danger to the distribution 
system is that leaks may not be locatable until water pressure is restored. 
For this reason it will take weeks to repair damage in densely populated 
areas. Fresh water for domestic purposes will have to be supplied by tankers 
to affected neighborhoods. Firef ghting efforts will in some areas be 
seriously hampered during the 72-hour period. 

Algermissen and others (1972, pg. 175) concluded that "Distribution system 
damage and water outages within San Francisco will be heavily accentuated in 



■116- 



the structurally poor ground areas which border the Bay in an irregular fash- 
ion, just as occurred in 1906. However, the anticipated good use of improved 
valving systems is expected to substantially reduce the loss of water due to 
broken mains. Similar water outages can be expected along all of the indus- 
trial and residential regions within the structurally poor ground areas along 
the Bay from San Francisco to San Jose. Elsewhere, the water distribution 
system is expected to remain mostly intact, and significant outages will be 
few and controllable, commensurate with availability of spare pipe, fittings, 
and accessability. For scenario purposes, 90% of the water outages in the 
structurally poor ground areas should be restored within 3 weeks by above 
ground piping similar to that which was used in San Fernando. 

Damage to facilities in counties other than San Francisco, Santa Clara, 
San Mateo, and Marin is expected to be nominal." 



Water Treatment Plants 

Treatment plant facilities will suffer damage, primarily where large pipe- 
lines connect with concrete structures and where pre-1960 concrete construc- 
tion does not involve adequate concrete column tie to floor and roof. Damage 
is expected to depend upon the periodicity of the concrete structures compared 
to pipeline and valve structures and result in diff icult-to-repair situations. 

Water treatment plants close to the San Andreas fault, or those built in 
structurally poor foundation material, will experience differential settlement 



-117- 



which will require shutdown of the plants, damage assessment, and significant 
repair. Plant bypass, with emergency chlorination, will be crucial during the 
72 hour period. 



Waste Disposal 

Many sewerage treatment facilities are located throughout the planning 
area, as evidenced by the locations shown on Map 1-W. Most of these systems 
involve gravity flow from the service area to the plant and discharge in an 
outfall to the Bay. Some systems involve pumping for all or part of their 
operation, a notable example being the "Super Sewer" of the East Bay Dis- 
chargers Authority which collects sewerage between San Leandro and Fremont 
(and from the Livermore Valley). Prolonged lack of electrical power for pump- 
ing and/or damage to system components at facilities along the Bay margin will 
necessitate sewerage discharge directly to the Bay. 

Movement of liquids in tanks and other containers can damage baffles and 
other equipment. In areas of structurally poor ground, treatment plant struc- 
tures may be on piling while pipelines are not. Differential response to 
shaking and consequent differential movements will cause damage where lines 
enter and leave structures. Various equipment — tanks, panel boards, etc. — 
that are poorly anchored will topple. For all of these various reasons, 
treatment plants are susceptible to significant damage, with the solution 
being to bypass the plant and discharge sewerage directly to the Bay. 

The vast majority of the many treatment plants which service the Bay area 
are located adjacent to the Bay in structurally poor ground environments that 



-118- 



are highly susceptible to ground failure. In most cases, the contiguous trunk 
sewers and outfalls are similarly located. As shown on Map 1-W, these many 
plants have been categorically designated as "Damaged/ Shutdown" based upon 
their location in areas of predicted intensity 8 (R-F) or greater and/ or loca- 
tion within the area of high potential for ground failure as shown on Map 
1-S. A few locations were marginal, in which cases, lacking the benefit of 
site-specific data, the author's judgment arbitrarily prevailed. 

Waste water treatment plants have only limited storage available. If the 
treatment sequence cannot be reestablished before storage capacity is exceed- 
ed, the waste water will be discharged, with emergency chlorination, if possi- 
ble, to reduce health hazards. In the Bay area, the discharge of raw sewerage 
can be expected to pollute most waterways, channels, harbors, and beaches, 
posing a serious public health hazard. 

Algermissen and others (1972, pg. 186) concluded that two-thirds of the 
raw sewerage produced in San Francisco, San Mateo, and Santa Clara counties 
should be assumed to be discharged into the Bay. 

Based upon the predicted intensities and the potential for ground failure 
that exists all around the Bay margins, we believe that this estimate could be 
extended to include an equivalent portion of the raw sewerage produced in the 
remaining areas that normally discharge to the Bay. 

The major impact of the earthquake on the sewerage collection systems will 
come as a result of ruptured sewer mains. According to Algermissen and others 
(1972, p. 184), the "damage will be mainly a function of the soil conditions, 



-119- 



and the damage patterns will follow those of the water distribution systems.... 
During the wet season, landslides will substantially increase the sewer damage 
in localized hillside areas, but these are not expected to be major problems. 
Experience from landslides has shown that the sewer line breaks can be dug out 
and the sewerage allowed to flow in open cuts... if necessary. This raw sewer- 
age may be a health hazard, but this should not be an insurmountable problem. 

For planning purposes, the damage patterns previously given for water 
distribution systems also apply here, except that the outage time can be sub- 
stantially less. From a practical standpoint, the sanitary sewer collection 
lines will not require significant use until the adjacent water distribution 
systems are restored." 

The following (Algermissen and others, 1972 s p. 183-4) relates to perfor- 
mance of sewers in San Francisco during the 1906 earthquake: "In the rocky 
portions of San Francisco the sewers were not affected. In portions where the 
rock was overlain with sand, there were no permanent displacements except 
where the original ground supported a fill; in such areas settlements occur- 
red, and the sewers were destroyed. In filled-in tidal areas, marshlands and 
swamps, there was considerable movement in a number of places (the greatest 
near 16th Street and Valencia Street, where the settlement was 5 feet and 
lateral movement six feet) and in all such disturbed areas the sewers were 
destroyed ( Transactions of the American Society of Civil Engineers , v. 59:214 
[1907])." 



-120- 



Planning Insights 

The various water agencies need to develop and continue public information 
programs to acquaint their water users with the prospects of contamination and 
loss of water supply and how to mitigate these potential problems. Plans for 
firefighting need to be coordinated with water agencies and alternative 
sources of water planned for in critical areas. Additional interconnections 
between the major water delivery systems should be considered to provide valu- 
able flexibility in regional water delivery operations, e.g., connections 
between the Hetch Hetchy Aqueduct and facilities of the East Bay Municipal 
Utility District and between the Hetch Hetchy Aqueduct and facilities of the 
Santa Clara Valley Water District. 



Recommended Further Work 

Water agencies need to examine their transmission and distribution systems 
in detail to identify areas and facilities most likely to be impaired. Ongo- 
ing programs should be maintained to progressively upgrade facilities of 
questionable seismic resistance in areas of high vulnerability. Capabilities 
to provide emergency distribution of water using ground transportation needs 
to be evaluated in areas which are identified as having significant possibil- 
ity of impaired water availability. Feasibility of providing additional 
interconnections between various transmission systems should be considered in 
order to provide alternative supply routes. A determination should be made of 
probable effects on the capability to deliver water to various portions of the 
Marin and San Francisco peninsulas assuming a prolonged lack of electrical 



■121- 



power for pumping. Fire fighting water requirements should be assessed in 
critical areas and estimates made of water supply impairment. 



WATER SUPPLY AND WASTE DISPOSAL 



MAP NOTATIONS 



Map 1-W 



NO . FACILITY COUNTY 



Wl Lake Merced Pumping Station San Francisco 

Out of of operation for more than 72 hours . 

This pumping station is critical to the water distribution system of San 
Francisco as a booster to high-level reservoirs. It is vulnerable both 
because of its location within an area of expected high shaking intensity 
and because it is dependent on commercial electric power and lacks an 
auxiliary power supply. 

W2 Broadmoor Pipelines San Mateo 

Out of operation for more than 72 hours . 

These two principal pipelines supplying water to San Francisco are locat- 
ed on overpasses over Interstate 280 in the Broadmoor area. 

W3 San Andreas Water Treatment Plant San Mateo 

Inoperable for more than 72 hours . 

This plant is vulnerable because of its proximity to the surface rupture 
and its dependence on commercial electric power without an auxiliary 
power supply. The plant can be bypassed without significant impact to 
the water supply system. 

W4 Hetch Hetchy Pipelines (North) Santa Clara 

Out of service for several weeks . 

Three major Hetch Hetchy pipelines, one cast iron, one riveted steel, and 
one welded steel, are all supported partly on shallow pilings, partly on 



-122- 



a steel bridge, and partly embedded In Bay mud. For planning purposes, 
these are expected to fail either by differential responses of the vari- 
ous supports to earthquake vibrations or by ground failure due to 
liquefaction. 

W5 Hetch Hetchy Pipelines (South) Santa Clara 

Open (Partial) . 

Four Hetch Hetchy pipelines, three of steel and one of prestressed con- 
crete, cross ravines on bridges in this area. Failure of one or more 
will occur at junctions of underground and elevated sections, but at 
least one will survive the earthquake. 

W6 City of Alameda Alameda 

Open (Partial). 

One or more of three cast iron pipelines that cross the estuary and 
supply the City of Alameda will be ruptured. 

W7 Penitencia Treatment Plant Santa Clara 

Closed for more than 72 hours . 

This water treatment plant and adjacent South Bay Aqueduct terminal 
facility will be inoperative for more than 72 hours because of seismi- 
cally-triggered landslide displacements. 

W8 Hetch Hetchy Pipelines Alameda 

Open . 

One or more of four Hetch Hetchy pipelines will fail due to ground 
failure resulting from liquefaction. 

W9 Mokelumne Aqueduct San Joaquin 

Out of operation . 

This major facility will be damaged as a result of a levee failure in the 
Delta. 

WTO Bon Tempe Treatment Plant Marin 

Closed . 

The Bon Tempe treatment plant will be out of service because of landslide 
damage. In any case, the plant will be inoperative because of electrical 
power failure. 



-123- 



Wll Southern Marin Pipeline Marin 

Out of service . 

This section of the Southern Marin Pipeline from Bon Tempe treatment 
plant will be ruptured due to slope failure. 

W12 San Geronimo Treatment Plant and Booster Station Marin 

Out of Service 

This facility and ancillary transmission pipelines will be damaged by 
intense shaking in this alluvial valley near the surface rupture. Damage 
to pumping plants and/or the possible lack of electrical power for an 
extended period would limit water supply deliveries to the urban areas 
that must be pumped from storage reservoirs. 

W13 North Bay Aqueduct Solano-Napa 

Open 

Facilities of the Putah South Canal and North Bay Aqueduct will be un- 
damaged. Only minor damage will occur at the treatment plant in Jameson 
Canyon. 

W14 Petaluma Aqueduct Sonoma-Marin 

Out of Service 

This facility is damaged by intense shaking and ground failure near 
Petaluma and Novate 



-124- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIO; ELECTRICAL POWER 

Map 1-E 



General Pattern 

The occurrence of the scenario earthquake will have a very significant 
impact on many of the major facilities that comprise the complex electrical 
power network serving this major urban area. (See Map 1-E.) Damage to power 
plants and their ancillary facilities within the planning area and In adjacent 
areas affected by the earthquake can be expected to result in a reduction in 
the combined generating capacity currently supplying the area with as much as 
50 percent of its needs. The potential impact of this reduction in local out- 
put is lessened, however, by the availability of power from other sources out- 
side the planning area and by the obvious significant reduction in consumer 
demand that will occur following the scenario earthquake. Immediate concerns 
will focus on repairs necessary to restore power within the damaged areas of 
greatest need. Major restoration problems include repairs necessary to route 
power through the major substations, restoration of damaged and collapsed 
transmission line towers, reactivation of equipment at local substations, and 
replacement of fallen poles, burned transformers, etc. 

It is a reasonable judgment that, during some portion of the first 72-hour 
period following the earthquake, virtually all portions of the area will have 
experienced some loss of power, at least temporarily. Algermissen and others 
(1972) estimated that "It is reasonable for planning purposes to consider 
50 per cent of the service connections in the study area to be without power 



-125- 



for 24 hours after a magnitude 8.3 shock.... in the congested portions of San 
Francisco and Oakland, the power outage should be considered at 100 percent 
for 24 hours, and thereafter at 75 percent for an additional 24 hours." 

Electrical power facilities on the Marin and San Francisco peninsulas are 
particularly vulnerable to damage from the scenario earthquake, and the time 
that it will take to restore full power under the best of conditions could be 
prolonged. While the resources may be available to expeditiously deal with 
repairs to the system, the many complicating factors involved in attempting to 
conduct an extensive repair operation amidst the confusion and damage to such 
lifelines as communications and highways will create a substantial challenge. 
Realistically, power is unlikely to be restored to many areas for extended 
periods of time. Emergency planning for power-dependent systems such as 
communications, water supply, fire fighting, and waste treatment should be 
very cognizant of this possible eventuality. 



Description 

The principal distributor of electrical power throughout the San Francisco 
Bay planning area is the Pacific Gas and Electric Company (P.G.&E.). Major 
power facilities within the planning area include four major power plants (two 
in San Francisco and two in Contra Costa County at Antioch and Pittsburg) , 
several smaller power plants, and an extensive network of major substations 
and interconnecting transmission lines that comprise the regional framework 
for the local distribution systems (see Map No. 1-E). Other major power fa- 
cilities that contribute a large percentage of the Bay area electrical supply 



-126- 



are located outside the planning area, but within the region which will be 
significantly effected by the scenario earthquake. These include: (a) Moss 
Landing Power Plant on Monterey Bay, (b) the generating complex consisting of 
15 relatively small power plants and related facilities at The Geysers Geo- 
thermal Area in Lake and Sonoma counties, and (c) transmission and switching 
facilities between these two power source areas and the planning area. 

We have considered the likelihood of damage to the various power plants, 
certain major substations, and power transmission lines. We have indicated 
locations where, as a basis for emergency response planning, there is a 
reasonable expectation of damage. These assumptions are based predominantly 
on the regional patterns of intensities and areas of potential ground failure 
as shown on Map No. 1-S. No geologic site analysis or engineering evaluation 
of specific facilities was performed. 



Power Plants 

According to Algermissen and others (1973, pg. 274), "Experience indicates 
that well-designed electrical generating plants should suffer minimum (less 
than 5%) damage in intensity VIII (MM) zones and only slight (less than 10%) 
damage in intensity IX (MM) zones." They note that damage at the Valley Steam 
Plant during the 1971 San Fernando earthquake was negligible though estimated 
ground motion of this plant was intensity VIII (MM). Plants, auxiliary 
switchyards, and other ancillary facilities located in areas of high ground 
water and/or poor soil conditions (such as Bay mud), however, are susceptible 
to significant damage as a result of ground failure. 



-127- 



The capacity of the major power generating facilities affected by this 
earthquake, aggregating about 7100 MW, is principally derived from the Moss 
Landing Power Plant, the four major plants in the Bay area, and those at The 
Geysers. Given the assumptions set forth in the damage assessments that 
follow, it is possible that only about half of this generating capacity may be 
available for some extended period following the scenario earthquake. This 
conclusion is based upon the possibility of damage to transmission lines as 
well as damage to the affected plants and their related facilities. 

While the impact of this potential loss of generating capacity is signifi- 
cant , the net impact upon the heavily damaged metropolitan service area can be 
ameliorated. Because P.G.&E. has access to other sources of power from out- 
side the affected area, it may be possible to reroute power to some consumers. 
The routine consumer needs for power will be far less than normal while both 
power generation and consumer facilities are being gradually restored. For 
planning purposes, all emergency operations and support systems necessary for 
responding to the scenario earthquake should have alternate power supply 
sources. 



Major Substations 

Transformer substations are essential to transmission both of locally 
generated power and of power available from outside the region affected by the 
earthquake. These substations, which contain banks of switches, circuit 
breakers, and massive transformers, are particularly vulnerable to damage by 
earthquake shaking. 



-128- 



On Map No. 1-E, several major substations are designated by a symbol indi- 
cating "significant damage at some, not all, locations." These substations 
are categorically considered because of their location within or very near 
areas of predicted intensity 9 (R-F) , as shown on the Seismic Intensity Dis- 
tribution Map (Map No. 1-S). Based upon this intensity pattern, it is a 
reasonable expectation that each of these stations will sustain some damage. 
In the absence of site-specific engineering and geologic evaluations, it is 
prudent for emergency planning purposes to conclude that damage is likely to 
occur at some substations sufficient to impair or curtail their performance 
seriously. The performance of these facilities should be further considered 
by emergency planners with the benefit of site-specific advice from the util- 
ity. Thus, while total failure is unlikely, parts of many substations will be 
damaged, and some of these will be incapacitated. In coping with such circum- 
stances, it should be noted that the utility has considerable flexibility with 
regard to routing power flow and, therefore, temporary reassignments may be 
possible. 

For planning purposes, it should be assumed that substations on the San 
Francisco peninsula, including the important Martin substation (see note E-8) , 
will be heavily damaged. The Ignacio substation, which serves most of Marin 
County, should also be assumed to be heavily damaged (see note E-9) . Such 
affects upon these critical facilities will further impair transmission of 
power to San Francisco and to Marin County until repairs are made. For plan- 
ning purposes , temporary repairs could permit transmission of some power with- 
in 12 hours or so (provided transmission lines are all intact), but complete 
repairs to these substations would involve a more extended repair period — 
possibly beyond 72 hours. 



-129- 



The conclusions of this investigation regarding the substations are in 
general agreement with those presented in the NOAA report. "Despite their 
good anchorages to power poles, to rails, and the like, many hundreds of 
transformers will be knocked out, and some will burn as they have in other 
earthquakes. Switchgear damage will result in serious power outages. Failure 
of porcelain insulators will additionally result in significant numbers of 
power failures" (Algermissen and others, 1972, p. 182). 



Transmission Lines 

Transmission towers and lines are principally subject to damage through 
secondary effects such as landslides. Conductor lines swinging together will 
only cause interruptions for a few seconds. 

Within the planning area, numerous major transmission routes traverse 
extensive areas subject to intense shaking and/or ground failure. Major 
230 KV transmission lines serving the San Francisco peninsula are routed 
across and around the perimeter of the south Bay and along the west Bay margin 
to San Francisco. Similar high-voltage lines serving Marin County traverse 
southern Napa and Sonoma counties. Lengthy segments of these facilities are 
located in Bay mud subject to ground failure. Many other major transmission 
lines, located along and across the surface rupture of the San Andreas fault 
in San Mateo, Santa Clara, Santa Cruz, and Marin counties, are vulnerable to 
intense shaking, surface fault rupture, and landsliding. 



-130- 



In view of the fact that numerous major routes are exposed to these 
hazards over extensive distances, it is a reasonable expectation that some of 
these major lines will be out of service because of damaged and collapsed 
towers. While the loss of a few towers would not pose a formidable situation, 
damage could be widespread and significantly compounded by landslides during a 
wet winter season or by fire caused by fallen lines during the dry season. 

While transmission lines in the East Bay area are also exposed to land- 
sliding and other ground failures, the degree of probable damage appears far 
less than in the areas on the west side of the Bay discussed above. 



Summary 



Algermissen and others (1972, pg. 182) concluded that "It is reasonable 
for planning purposes to consider 50% of the service connections in the study 
area to be without power for 24 hours after a magnitude 8.3 shock.... In the 
congested portions of San Francisco and Oakland, the power outage should be 
considered at 100% for 24 hours, and thereafter at 75% for an additional 24 
hours.... For scenario purposes, an 8.3 magnitude earthquake on the San 
Andreas fault will require the use of all standby power facilities throughout 
San Francisco, San Mateo, and Santa Clara counties, and 50% of. standby power 
facilities in Marin, Contra Costa, and Alameda counties." In the event of 
major damage to the Ygnacio substaion near Novato, compounded by possible 
damage to transmission lines in this area, as assumed in this scenario, Marin 
County will also be highly dependent upon standby power facilities. 



-131- 



Recovery time for transmission of electrical power will be different from 
place to place in the Bay area, but San Francisco, Marin, and San Mateo 
counties can be expected to be without power for the most lengthy period 
because of the more vulnerable nature of the corridor through which power is 
routed to these areas. Steinhardt (1978) points out that "in a great earth- 
quake, a large number of users will be without power, temporarily at least, 
and that.... It is reasonable to expect that the rate of service restoration 
will exceed the rate of recovery of customer demand." On the other hand, it 
is the judgment of Algermissen and others (1972, p. 182-183) that "the repair 
of the very extensive damage will require logistic support which, in our opin- 
ion, will require many days to restore even all vital services. It must be 
remembered that blocked streets and roads, higher priority medical require- 
ments, and aftershocks preclude any perfect response effort to the power out- 
ages to be expected. The unexpected can and does happen as it did in the 
power blackouts a few years ago in the northeastern states." 

IT IS ASSUMED IN THIS 1982 SCENARIO THAT ALL CRITICAL FACILITIES SUCH AS 
HOSPITALS, FIRE AND POLICE STATIONS, EMERGENCY COMMUNICATIONS AND OPERATION 
CENTERS, AND WATER PUMPING STATIONS WILL REQUIRE STANDBY GENERATING EQUIPMENT 
AND EMERGENCY FUEL SUPPLIES IN SAN FRANCISCO, SAN MATEO, SANTA CLARA, AND 
MARIN COUNTIES. 



Planning Insights 

Society has evolved to where it is highly dependent upon a continuous 
supply of electrical power to meet a myriad of everyday needs. Indeed, the 



■132- 



human environment within modern high-rise structures is entirely controlled by 
it. Consequently, everyone, particularly those entities responsible for main- 
tenance of lifelines and critical facilities, should examine their ability to 
function in the event of a prolonged absence of electrical power. 

At the individual citizen level, the following is very appropriate. Com- 
menting upon the lack of electrical power in Santa Cruz County that resulted 
from landsliding during the intense storm of January 4, 1982, Stegner (1982) 
concluded: "It may be a long time before we need to dig out our old boy scout 
manuals again, but, while we sit around waiting for the killer earthquake that 
everybody seems to regard as inevitable, we might take a lesson from the 
killer storm that nobody expected. The difference between misery and comfort, 
relatively speaking, may be no more than a can of kerosene and a can of gaso- 
line in the garage, a can of soup in the larder, and a half dozen flashlight 
batteries in the kitchen drawer. What was the motto? Be prepared?" An 
intensive public education program to condition people to expect power outages 
after the earthquake is clearly appropriate. 



Recommended Further Work 

The critical power corridors and facilities should be examined in light of 
the best geologic data available to assess the vulnerability of specific ele- 
ments in the electrical power network. Capability to respond and accomplish 
timely repairs to a widespread affected area as described in this scenario 
needs to be evaluated further. Probable interruptions of other lifelines that 
are discussed in this report, especially water supply, waste treatment, and 



-133- 



communications, must be taken into account in planning an earthquake-emergency 
response for this utility. Strategies for repair of facilities must take into 
account the post-earthquake feasibility of ground and other means of transpor- 
tation. Strategies for rerouting power into the area to augment decreased 
capacity within the region should also be emphasized. Public education should 
be undertaken to contend with the power outages. 



ELECTRICAL POWER 



MAP NOTATIONS 



(See Map 1-E.) 



NO. FACILITY COUNTY 



El Moss Landing Power Plant Monterey 

Moss Landing Power Plant (capacity 2060 MW) is located on Monterey Bay, 
some 18 km west of and near the southern limit of surface rupture on the 
San Andreas fault, as assumed in this scenario. This area suffered ex- 
tensive ground failure due to liquefaction during the 1906 earthquake 
(Youd and Hoose, 1978). Although the power plant is located on bedrock 
(Hoose, 1982, personal communication) and, presumably, susceptible only 
to damage by shaking, the auxiliary switchyards, fuel handling and stor- 
age facilities, and nearby transmission towers are assumed to be vulner- 
able to damage by ground failure as well as shaking. In addition, major 
power transmission routes from Moss Landing to the San Francisco Bay area 
must cross both the surface rupture and the Santa Cruz Mountains in steep 
terrain subject to landslides and consequent tower damage. Considering 
these various possibilities, we have assumed that power from Moss Landing 
will be unavailable for at least the 72-hour post-earthquake period. 
Algermissen and others (1972, pg. 182) concluded previously that "Suffi- 
cient damage will occur to power generating facilities on the San 
Francisco and Moss Landing sites to require shut-down." 

E2 Potrero and Hunters Point Power Plants San Francisco 

Shutdown of the Potrero and Hunters Point Power Plants (combined capaci- 
ty, 896 MW) , located near the Bay margin and subjected to intense shaking 



-134- 



and ground failure, is a reasonable expectation for planning purposes. 
Algermissen and others (1972, pg. 182) also assumed that these two plants 
would be shutdown as a result of a similar M 8+ scenario earthquake. 

E3 Pittsburg and Contra Costa Power Plants Contra Costa 

Algermissen and others (1972, pg. 182) concluded that these plants would 
remain operational. Though the prospects of significant damage to these 
plants is probably remote, both the plants and their related facilities 
are located on or near Bay Mud, which may be subject to ground failure. 
For planning purposes, therefore, we have assumed that sufficient damage 
will occur to plant facilities to reduce the combined power output of 
the two plants by 15 percent. 

E4 Moraga Transmission Line Contra Costa 

This power transmission line to the East Bay crosses a large landslide 
immediately west of the Moraga substation, and while the substation will 
survive both the shaking and a reactivation of the landslide, the trans- 
mission line will not. 

E5 The Geysers Geothermal Area Sonoma-Lake 

Currently, some fifteen power plants in The Geysers Geothermal Area have 
a total generating capacity of about 900 MW. Turbines are driven by 
steam piped to the plants from some 200 wells. Located some 50 km east 
of the San Andreas fault, earthquake intensity at The Geysers will be 
7 (R-F) or less. The earthquake will, however, have a significant impact 
upon the generating capacity of the area as a result of landslides on 
steep unstable slopes, a problem compounded during the wet winter sea- 
son. Landslides could cause serious damage to any one or all powerrelat- 
ed facilities in The Geysers, i.e. certain of the older power plants, the 
steam producing wells, the extensive above-ground steam piping, and power 
transmission lines routed across steep mountainous terrain. In addition 
to these, the road system within The Geysers area is also extremely vul- 
nerable to landslides, a factor which could cause a major impediment to 
timely repairs. For planning purposes, we have assumed that production 
of electrical power in The Geysers area is diminished by one-third as a 
result of this scenario earthquake. 

E6 Power Plant Fuel Line Contra Costa 

The oil supply pipeline between Richmond and the Pittsburg and Contra 
Costa power plants crosses areas susceptible to ground failure by lique- 
faction; but no damage to this line is forecast. In any event, repairs 
could be accomplished rapidly. The availability of electrical power for 
pumping and the integrity of pumping equipment may be a more critical 
consideration. 



-135- 



E7 Oakland Power Plant Alameda 

This relatively small plant is susceptible to intense shaking and ground 

failure. We have, for planning purposes, concluded that this plant will 
be shutdown for at least 72 hours. 



E8 Martin Substation San Mateo 

This substation is located in an area of predicted intense shaking and 
possible ground failure, and major damage to some equipment at this 
station is a reasonable expectation. Routing of power through this 
critical station constitutes a major consideration in the planning for 
restoration of power to the City. 

E9 Ygnacio Substation Marin 

This critical substation handles all power routed south into Marin 
County. Prudent planning should allow that this facility, founded on 
shallow Bay mud, could be seriously damaged by shaking and/or ground 
failure. 



-136- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIO 

For Q Mogmtude 8 3 Earthquake on the Son Andreas Faull in 
the San Francisco Boy Area 




EARTHQUAKE PLANNING SCENARIO: NATURAL GAS 
Map 1-G 



General Pattern 

Damage to natural gas facilities will consist primarily of (a) some iso- 
lated breaks in the major transmission lines and (b) innumerable breaks in 
mains and individual service connections within the distribution systems, 
particularly in the areas of intense shaking and/ or poor ground nearer the Bay 
margins. For planning purposes, it should be considered that these many leaks 
in the distribution system will affect a major portion of the urban areas in 
the East Bay, the South Bay, and the San Francisco and Marin peninsulas 
resulting in a loss of service for extended periods. Sporadically distributed 
fires should be expected at the sites of a small percentage of ruptures both 
in the transmission lines and the distribution system. 

Transmission pipelines serving the San Francisco Peninsula are most vul- 
nerable to damage. Damage and repair problems to major transmission lines in 
the East Bay should not be significant. No significant damage to transmission 
facilities in the North Bay is envisioned. 



Description 

Natural gas is supplied to the region through facilities of the Pacific 
Gas and Electric Company (P.G.&E.). The major gas transmission lines that 



-137- 



serve the San Francisco Bay area are shown on Map 1-G. Locations of the sev- 
eral gas storage holders and terminals are also indicated. 

Damage to the gas transmission lines and related facilities will be con- 
centrated in the areas of poor ground around the Bay margin. Some pipeline 
damage will occur as a result of fault rupture on the Peninsula and as a 
result of seismically-triggered landslides near Upper Crystal Springs Reser- 
voir and in the hills east of Fremont. 

The low pressure gas storage facilities (holders) have numerous seals and 
are expected to develop leaks as a result of shaking. The holders, which are 
not particularly crucial to the supply system, can be bypassed, and the gas 
transmission systems will still be operational provided the transmission mains 
have not been ruptured. 

Many gas leaks will occur within the distribution mains and individual 
service connections, particularly in the areas that experience ground failure 
due to settlement, liquefaction, or seismically-triggered landslides. It can 
be expected that natural gas will be unavailable to all or parts of most urban 
areas in the East Bay, South Bay, and San Francisco Peninsula for an extended 
period of time. "An important consideration with gas is that the complete 
loss of supply to a large number of customers is a serious matter in itself. 
Unlike electricity, which can usually be turned off and on at will, the re- 
storation of gas service is an expensive and time-consuming task. If a pipe- 
line is broken, or part of a distribution network loses all pressure, every 
customer being supplied from that network must individually be shut down 
before repressuring can begin. To prevent explosions, the entire system of 



-138- 



mains, feeders, and service lines in the affected area must be purged before 
pilot lights can be relighted and service restored. In addition, extensive 
gas leak detection surveys may be needed, using flame ionization equipment 
throughout the affected area" (California Public Utilities Commission, LNG 
Task Force, 1980). 

Algermissen and others (1972) concluded earlier that "An 8.3 magnitude 
shock on the San Andreas fault probably will not cause excessive damage to the 
natural gas system, although localized outages will require extensive repair 
periods.... However, the transmission lines do pass through potentially un- 
stable ground regions along San Francisco Bay." 



Planning Insights 

The various major utilities should collaborate in continuing public educa- 
tion programs to explain the probable consequence of a major earthquake on 
their service capabilities and what actions should be taken by the public to 
mitigate the effects. 



Recommended Further Work 

In areas of poor ground where potential for major pipeline failures exist, 
alternative line(s) in stable materials should be considered. The adequacy 
and location of automatic pressure-activated shut-off valves should be period- 
ically reviewed in the light of new geologic Information concerning potential 
problem areas. 



-139- 



Locations where gas availability would be most severely impacted should be 
identified. Emergency users of natural gas should be identified. The likeli- 
hood of fire due to breaks in local gas mains should also be investigated. 



NATURAL GAS 



MAP NOTATIONS 



(See Map 1-G) 



NO . LOCATION COUNTY 



Gl Richmond Contra Costa 

Pipeline rupture will occur due to ground failure. 

G2 SFO Pipeline San Mateo 

Rupture of old pipeline sections will occur due to ground failure caused 
by liquefaction. "For planning purposes, the transmission line skirting 
the west side of the Bay is estimated to be out of service due to ground 
failure" (Algermissen and others, 1972, p. 180). 

G3 San Andreas Fault San Mateo 

Rupture of pipelines will occur due to ground breakage along the San 
Andreas fault zone between San Andreas Lake and Route 1. Water pipelines 
ruptured and telescoped at this location during the 1906 event (Harry 
Tracy, San Francisco Water Department, oral communication, 1982). Pipe- 
line rupture will also occur near Upper Crystal Springs Reservoir 
(between San Mateo Creek and 4 kilometers southeast of the junction of 
Interstate 280 and Route 92) due to landslides. 

G4 Coyote Creek Alameda-Santa Clara 

The terminal will be damaged and pipelines will rupture due to ground 
failure caused by widespread liquefaction. 



-140- 



G5 Newark Alameda 

Ground failure will affect pipelines and there will be some damage to the 
terminal. 



G6 Sunol Area Alameda 

One or more pipeline ruptures will occur due to landslides triggered by 
the earthquake. 

G7 Oakland to San Jose Alameda 

The pipeline will be ruptured along this route due to ground failure 
caused by liquefaction. 

G8 Oakland Waterfront Alameda 

Pipeline rupture will occur due to ground failure caused by liquefaction. 



-141- 



-142- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



EARTHQUAKE PLANNING SCENARIO: PETROLEUM FUELS 

Map 1-P 



General Pattern 

Following the scenario earthquake, operations at the several major refin- 
eries in the Bay area will be curtailed until all facilities are thoroughly 
inspected and repairs accomplished. Pipelines are expected to withstand the 
shaking without significant impairment, but ruptures can be expected wherever 
contrasting support conditions are modified by differential movements and 
ground failure occurs due to liquefaction or seismically-triggered land- 
slides. Large storage tanks and marine loading facilities located on poten- 
tially responsive foundation materials are also subject to damage. 



Description 

Important petroleum-related facilities that could sustain significant dam- 
age as a result of the scenario earthquake include (a) the several major 
refineries located on San Pablo Bay and east of the Carquinez Straits, (b) 
several critical petroleum product pipelines connecting these refineries to 
distribution terminals near San Francisco and Oakland International Airports 
and in San Jose, and (c) Bayside oil-handling facilities for marine (tanker) 
transport. 

Refineries are extremely complex facilities, and the prediction of their 
behavior during the earthquake is beyond the scope of this study. Refining 



-143- 



and/or storage facilities at each of the major refineries (see Map No. 1-P) 
are located upon or in proximity to the estuarine Bay mud and marsh deposits 
that are most susceptible to ground motion amplification and liquefaction with 
possible ground failure. Site-specific studies will be required to determine 
the extent of vulnerability to each facility's refining and storage capability. 

The several major petroleum product pipelines that serve the metropolitan 
area cross extensive areas of structurally poor ground near the Bay margin. 
Ground failures resulting in distinct differential movements could cause pipe 
rupture in these areas. Pipe connections at the terminal facilities are also 
vulnerable due to the differing response between buried pipe and rigid 
structures. 

Algermissen and others (1972, p. 186) pointed out that "There are other 
complicating factors related to petroleum pipelines. In so far as it is 
known, none of these pipelines have automatic shut-off valves. If the rupture 
occurs during the height of the dry season in the Berkeley Hills and other 
surrounding areas, fire could be a very serious problem. This could also be 
widespread during the rainy season, should the petroleum ignite as it is 
washed downstream rapidly with storm waters into the sewers." 

Shut-off valves are installed on many of these pipelines, and will auto- 
matically function when the line pressure drops below a particular threshold, 
such as would occur in the case of a pipe rupture. These valves are commonly 
dependent upon electrical power, however, so in the event of a major earth- 
quake and possible large-scale power loss, these valves would not perform. 



-144- 



Those refineries having marine terminals can anticipate some damage to 
these facilities as a result of intensity 8-9 (R-F) shaking and high potential 
for ground failure common to all Bayside refinery locations. 



Planning Insights 

Plans should be developed to ensure distribution of fuel to those loca- 
tions designated for emergency response operations, including airports. 
Appropriate facilities, including emergency power and pumping capability, 
should be available at fuel storage locations for refueling of helicoptors and 
other emergency vehicles. Major damage to the trans-Bay product lines could 
seriously impact fuel availability on the San Francisco peninsula. 



Recommended Further Work 

All petroleum product pipelines serving the metropolitan areas should be 
examined in detail relative to their exposure to ground failure. The adequacy 
and locations of automatic shut-off valves should be examined on all product 
lines and remedial measures undertaken, as appropriate, to ensure a functional 
system. Locations of fuel storage facilities, including those for aviation 
fuels, should be predetermined and emergency procedures established to ensure 
that these supplies will be available when needed. An inventory of fuel 
storage facilities throughout the area would facilitate planning of emergency 
response efforts that will be dependent upon nearby sources of fuel. 



-145- 



The need for fire fighting emergency plans to cope with pipeline ruptures 
should be considered — particularly for areas where the pipelines are con- 
sidered to be most vulnerable to this effect. 



PETROLEUM FUELS 



MAP NOTATIONS 



(See Map 1-P) 



NO. 



FACILITY 



COUNTY 



PI Terminal Facilities in the Richmond Area 



Contra Costa 



Poor ground conditions and differential movements at the junctures of 
pipelines and terminal facilities will result in moderate damage. 



P2 Coyote Creek 



Alameda-Santa Clara 



The area near the mouth of Coyote Creek suffered extensive ground failure 
due to liquefaction during the 1906 earthquake (Youd and Hoose, 1978). 
Pipelines are subject to failure due to lateral spreading caused by 
liquefaction. 



P3 Oakland to San Jose Alameda 

Pipeline failure will occur along this route due to ground failure. 

P4 Alameda - Bay Crossing Alameda 

Differential movement will produce damage where the pipelines enter the 
Bay, but the Bay crossings themselves will survive. 

P5 Albany to Oakland Alameda 

Pipeline rupture will occur along this route due to ground failure. 



P6 Richmond - Crockett 

Pipeline damage will occur due to ground failure. 



Contra Costa 



-146- 



P7 Mormon Temple Landslide Alameda 

Pipeline rupture due to landslide movement. 

A reactivation of this landslide within the Hayward fault zone has previ- 
ously caused pipeline rupture at this location. 

P8 Fuel Terminals - Vicinity Oakland International Airport Alameda 

Ground failure or differential movement of structures will rupture pipe- 
lines at the junctions with terminals. 

P9 Martinez Contra Costa 

Ground failure will cause numerous pipeline ruptures in this area of many 
pipeline facilities. 

P10 Sunol Area Alameda 

Pipeline rupture will occur due to a seismically-triggered landslide. 

Pll Suisun Marsh Solano 

Pipeline rupture will occur due to settlement or lateral spreading caused 
by liquefaction similar to that produced here in the 1906 earthquake. 

P12 Honker Bay Solano 

Pipeline rupture will occur due to settlement or lateral spreading caused 
by liquefaction similar to that produced here in the 1906 earthquake. 



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-148- 



THIS MAP IS INTENDED FOR 
EMERGENCY PLANNING PURPOSES ONLY 



IT IS BASED UPON THE FOLLOWING HYPOTHETICAL 
CHAIN OF EVENTS: 

1. A PARTICULAR EARTHQUAKE OCCURS 

2. VARIOUS LOCALITIES IN THE PLANNING AREA 
EXPERIENCE A SPECIFIC TYPE OF SHAKING OR 
GROUND FAILURE 

3. CERTAIN CRITICAL FACILITIES UNDERGO DAMAGE 
AND OTHERS DO NOT 

THE CONCLUSIONS REGARDING THE PERFORMANCE OF 
FACILITIES ARE HYPOTHETICAL AND NOT TO BE 
CONSTRUED AS SITE-SPECIFIC ENGINEERING 
EVALUATIONS. FOR THE MOST PART, DAMAGE 
ASSESSMENTS ARE STRONGLY INFLUENCED BY THE 
SEISMIC INTENSITY DISTRIBUTION MAP FOR THIS 
PLANNING AREA. THERE IS DISAGREEMENT AMONG 
INVESTIGATORS AS TO THE MOST REALISTIC MODEL FOR 
PREDICTING SEISMIC INTENSITY DISTRIBUTION. NONE 
HAVE BEEN FULLY TESTED AND EACH WOULD YIELD A 
DIFFERENT EARTHQUAKE PLANNING SCENARIO. 
FACILITIES THAT ARE PARTICULARLY SENSITIVE TO 
EMERGENCY RESPONSE WILL REQUIRE A DETAILED 
GEOTECHNICAL STUDY. 

THE DAMAGE ASSESSMENTS ARE BASED UPON THIS 
SPECIFIC SCENARIO. AN EARTHQUAKE OF 
SIGNIFICANTLY DIFFERENT MAGNITUDE ON THIS OR ANY 
ONE OF MANY OTHER FAULTS IN THE PLANNING AREA 
WILL RESULT IN A MARKEDLY DIFFERENT PATTERN OF 
DAMAGE. 



GLOSSARY 



(Definitions adapted from Glossary of Geology, American Geological 
Institute, 1981, and American Heritage Dictionary, 1981) . 



ALLUVIUM 



BEDROCK 



DEFORMATION 



EARTHQUAKE 



EARTHQUAKE INTENSITY 



EARTHQUAKE MAGNITUDE 
FAULT 

GROUND FAILURE 

GROUND RUPTURE 
ISOSEISMAL AREA 
LIFELINES 



LIQUEFACTION 



Surficial sediments consisting of poorly consolidated 
gravels, sands, silts, and clays deposited by flowing 
water. 

A general term for coherent, usually solid rock, that 
underlies soil or other unconsolidated surficial 
material. 

A general term for the process of folding, faulting, 
shearing, compression, or extension of rocks. 

Vibratory motion propogating within earth or along 
its surface caused by the abrupt release of strain 
(elastically deformed rock) by displacement movement 
along a fault surface. 

A measure of the effects of an earthquake at a parti- 
cular place. Intensity depends upon the earthquake 
magnitude, distance from epicenter, and upon the 
local geology. 

A measure of the size of an earthquake, as determined 
by measurements from seismographic records. 

A fracture (rupture) or a zone of fractures along 
which there has been displacement of adjacent earth 
material. 

Permanent ground displacement produced by fault rup- 
ture, differential settlement, liquefaction, or slope 
failure. 

Displacement of the earth's surface as a result of 
fault movement associated with an earthquake. 

An area composed of points of equal earthquake inten- 
sity on the earth's surface. 

Facilities such as highways, bridges, tunnels, major 
airports, electrical power lines, fuel pipelines, 
communication lines, water supply lines, marine ter- 
minals and railroads. 

The transitory transformation of sandy water-saturat- 
ed alluvium with properties of a solid into a state 
possessing properties of a liquid as a result of 
earthquake shaking. 



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MAGNITUDE 

MODIFIED MERCALLI 
SCALE 

REINFORCED MASONRY 

RICHTER SCALE 

ROSSI-FOREL SCALE 

SEISMIC HAZARD 

THRUST FAULT 



WATER TABLE 



See Earthquake Magnitude. 
See Appendix, 

Masonry construction with steel reinforcement. 

See Appendix. 

See Appendix. 

A condition of risk or potential damage due to an 
earthquake. 

A fault with a dip of 45° or less over much of its 
extent, on which the hanging wall appears to have 
moved upward relative to the footwall. Horizontal 
compression rather than vertical displacement is its 
characteristic feature. 

The upper surface of ground water saturation of pores 
and fractures in rock or surficial earth materials. 



-150- 



REFERENCES 

Algermissen, S.T., Rinehart, W.A., Dewey, James, Steinbrugge, K.V., Lagorio, 
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Gordon, R.F., 1972, A study of earthquake losses in the San Francisco Bay 
area: Data and analysis: National Oceanic and Atmospheric Administration 
report prepared for the Office of Emergency Preparedness, 220 p. 

Algermissen, S.T., Hopper, Margaret, Campbell, Kenneth, Rinehart, W.A., Per- 
kins, David, Steinbrugge, K.V., Lagorio, H.J., Moran, D.F., Cluff, L.S., 
Degenkolb, H.J., Duke, CM., Gates, G.O., Jacobsin, D.W., Olsen, R.A. and 
Allen, C.R., 1973, A Study of earthquake losses in the Los Angeles, Califor- 
nia area; data and analysis: National Oceanic and Atmospheric Administra- 
tion report prepared for the Federal Disaster Assistance Administration, 
331 p. 

Barosh, P.J., 1969, Use of seismic intensity data to predict the effects of 
earthquakes and underground nuclear explosions in various geologic settings: 
U.S. Geological Survey Bulletin 1279, 93pp. 

Bishop, C.C., Knox, R.D., Chapman, R.H., Rodgers, D.A., and Chase, G.B., 1973, 
Geological and geophysical investigations for Tri-cities seismic safety and 
environmental resource study: California Division of Mines and Geology 
Preliminary Report 19, 44 p. 

Blake, M.C., Jr., Bartow, J. A., Frizzell, V.A., Jr., Schlocker, J., Sorg, D. , 
Wentworth, CM., and Wright, R.H., 1974, Preliminary geologic map of Marin 
and San Francisco counties and parts of Alameda, Contra Costa and Sonoma 
counties, California: U.S. Geological Survey Basic Data Contribution 64 
(Miscellaneous Field Studies Map MF-574). 

Borcherdt, R.D., Gibbs, J.F., and Lajoie, K.R. , 1975, Prediction of maximum 
earthquake intensity in the San Francisco Bay region, California, for large 
earthquakes on the San Andreas and Hayward Faults: U.S. Geological Survey 
Field Studies Map MF-709. 

California Department of Water Resources, 1981, Maps showing water table eleva- 
tions in parts of northern San Francisco Bay. 

Castenada, Joan, 1981, Letter to James F. Davis, State Geologist, December 2, 
1981, from the Airport Director, Hayward Air Terminal, concerning a prelimi- 
nary version of the Earthquake Planning Scenario for highways and airports. 
Includes interoffice report of 9/18/81 concerning pavement load capacities. 

CDOT (California Department of Transportation), 1981, Scenario of effects on 
state transportation for an 8.3 earthquake along the northern San Andreas 
fault. Written communication from CALTRANS to the State Geologist, Sept. 1, 
1981, 13 p. 

Contra Costa County Planning Department, 1974, Technical report for the seismic 
safety element (draft): A report of the Contra Costa land use and transpor- 
tation study, 263 p. 



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County of Santa Clara Planning Department, 1976, Seismic safety plan: An ele- 
ment of the general plan, Santa Clara County. 119 p. 

Dehaesus, A.A. , and Nelson, Todd, 1981, Letter to James F. Davis, State Geolog- 
ist, November 9, 1981, from the Director of Planning and the Senior Planning 
Geologist, Contra Costa County Planning Department concerning their review 
of a preliminary version of the Earthquake Planning Scenario for highways 
and airports. 

Eggleston, Buzz, 1980, Peninsula overpasses that pose quake risk: Times Tri- 
bune Weekly (North), Wednesday, November 19, 1980. 

Evernden, J.F., Hibbard, R.R., and Schneider, J.F., 1973, Interpretation of 
seismic intensity data: Seismological Society of America Bulletin, v. 63, 
p. 399-422. 

Evernden, J.F., Kohler, W.M. , and Clow, G.D., 1981, Seismic intensities of 
earthquakes of conterminous United States — Their prediction and interpreta- 
tion: U.S. Geological Survey Professional Paper 1223, 50 p. 

Finlayson, D.J., 1982, Emergency response for plan annex - water and waste dis- 
posal systems, Draft report for Governor's Emergency Task Force on Earth- 
quake Preparedness, dated January 26, 1982. 

Helley, E.J., Lajoie, K.R., and Burke, D.B., 1972, Geologic map of late Ceno- 
zoic deposits, Alameda County, California: U.S. Geological Survey Basic 
Data Contribution 48. 

Jacobs, A.B., 1974, Community safety plan: A proposal for citizen review: San 
Francisco Department of City Planning, 68 p. 

Laird, R.T., and others, 1979, Quantitative land-capability analysis: U.S. 
Geological Survey Professional Paper 945, 115 p. 

Lajoie, K.R., Helley, E.J., Nichols, D.R., and Burke, D.B., 1974, Geologic map 
of unconsolidated and moderately consolidated deposits of San Mateo County, 
California: U.S. Geological Survey Basic Data Contribution 68 (Miscellane- 
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Lanferman, P.E., and Danehy, E.A. , 1981, Letter to James F. Davis, State Geo- 
logist, November 12, 1981, from the Engineer-Manager and the Engineering 
Geologist, Public Works Agency, County of Alameda, concerning a preliminary 
version of the Earthquake Planning Scenario for highways and airports. 

Lawson, A.C., and others, 1908, The California earthquake of April 18, 1906, 
Report of the State Earthquake Commission (2 v. and atlas): Carnegie 
Institution of Washington, Washington, D.C. 

LNG Task Force, 1980, Recommendations for an earthquake hazards reduction pro- 
gram. Report prepared for the California Seismic Safety Commission by the 
California Public Utilities Commission, San Francisco, California. 



-152- 



Louis, E.B., 1981, Letter to Jack Bennett, C.D.M.G., December 4, 1981, from the 
Principal Civil Engineer, Public Works, Department of Private Development, 
City of San Jose, concerning the comments made by Ron Mearns, the City 
Engineering Geologist, on a preliminary version of the Earthquake Planning 
Scenario. 

Lunn, David, 1982, Areas of high ground water (less than 30 feet) in the Liver- 
more Valley: Written communication, Alameda County Flood Control and Water 
Conservation District, Zone 7. 

McCarty, J.R., 1981, Letter to James F. Davis, State Geologist, November 12, 
1981, from the Director of Public Works, City of Oakland, concerning a 
preliminary version of the Earthquake Planning Scenario. 

Nason, Robert, 1980a, Damage in San Mateo County, California in the earthquake 
of 18 April 1906: U.S. Geological Survey Open-File Report 80-176, 49 p. 

Nason, Robert, 1980b, Damage in Santa Clara and Santa Cruz counties, California 
caused by the earthquake of 18 April 1906. U.S. Geological Survey Open-File 
Report 80-1076, 63 p. 

Nason, Robert, 1982, Damage in Alameda and Contra Costa counties, California, 
in the earthquake of 18 April 1906: U.S. Geological Survey Open-File Report 
82-63, 41 p. 

Nichols, D.R., and Wright, N.A., 1971, Preliminary map of historic margins of 
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Contribution 9. 

Perkins, Jeanne, and others, 1981, A guide to ABAG's earthquake hazard mapping 
capability: Association of Bay Area Governments, Berkeley, California. 

Rice, S.J., 1973, Geology and geologic hazards of the Novato area, Marin Coun- 
ty, California: California Division of Mines and Geology Preliminary Report 
21, 47 p. 

Rice, S.J., 1975, Geology for planning: Novato area, Marin County, California: 
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Sims, J.D., Fox, K.F., Jr., Bartow, J. A., and Helley, E.J., 1973, Preliminary 
geologic map of Solano County and parts of Napa, Contra Costa, Marin and 
Yolo counties, California: U.S. Geological Survey Basic Data Contribution 
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Snyder, W.G., 1981, Letter to James F. Davis of CDMG, November 30, 1981, from 
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nary version of the Earthquake Planning Scenario for railroads. 



-153- 



Stegner, P., 1982, Rained Out, California Magazine, March, 1982. 

Steinhardt, O.W., 1978, Protecting a power lifeline against earthquakes: 
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Stiver, N.W. , 1981, Letter to James F. Davis, State Geologist, November 9, 
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Troup, V.B., 1971, Soil test holes: Airport Department, City of San Jose, Cal- 
ifornia (Blueprint of airport layout and analyses of 150 soil borings). 

Troup, V.B., 1981, Letter to James F. Davis, State Geologist, December 2, 1981, 
from the Deputy Director, Airport Planning & Development, Airport Depart- 
ment, City of San Jose, concerning a preliminary version of the Earthquake 
Planning Scenario for highways and airports. 

U.S. Geological Survey, 1981, Scenarios of possible earthquakes affecting maj- 
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Walford, J.M., and Kermit, M.L., 1981, Letter to James F. Davis, State Geolog- 
ist, November 13, 1981, from the Public Works Director and Deputy Public 
Works Director, Contra Costa County Public Works Department, concerning pre- 
paredness of Buchanan Field in the event of a major earthquake on the San 
Andreas fault. 

Webster, D.A. , 1973, Map showing areas bordering the southern part of San Fran- 
cisco Bay where a high water table may adversely affect land use: U.S. Geo- 
logical Survey Basic Data Contribution 61 (Miscellaneous Field Studies Map 
MF-530) . 

Woolfe, D.A., and others, 1975, Seismic and safety elements of the general 
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Technical supplement (draft), 108 p. 

Youd, T.L., and Hoose, S.N., 1978, Historic ground failures in northern Cali- 
fornia triggered by earthquakes: U.S. Geological Survey Professional Paper 
993, 177 p. 



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APPENDIX 



Rossi-Forel Scale, 

Modified Mercalli Scale, 

and Richter Scale 



-155- 



-156- 



EARTHQUAKE-MEASURING SCALES 



ROSSI-FOREL INTENSITY SCALE 

The first scale to reflect earthquake intensities was developed in the 
1880s by de Rossi of Italy and Forel of Switzerland. This scale, with values 
from 1 to 10, was used for about two decades. The most commonly used form of 
the Rossi-Forel (R-F) scale reads as follows: 

1* Microseismic shock . Recorded by a single seismograph or by 
seismographs of the same model, but not by several seismographs 
of different kinds; the shock felt by an experienced observer. 

2 Extremely feeble shock . Recorded by several seismographs of 
different kinds; felt by a small number of persons at rest. 

3 Very feeble shock . Felt by several persons at rest; strong 
enough for the direction or duration to be appreciable. 

4 Feeble shock . Felt by persons in motion; disturbance of 
movable objects, doors, windows, cracking of ceilings. 

5 Shock of moderate intensity . Felt generally by everyone; dis- 
turbance of furniture, beds, etc., ringing of some bells. 

6 Fairly strong shock . General awakening of those asleep; 
general ringing of bells; oscillation of chandeliers; stopping 
of clocks; visible agitation of trees and shrubs; some startled 
persons leaving their dwellings. 

7 Strong shock . Overthrow of movable objects; fall of plaster; 
ringing of church bells; general panic, without damage to 
buildings. 



Very strong shock , 
buildings. 



Fall of chimneys; cracks in the walls of 



Extremely strong shock , 
buildings. 



Partial or total destruction of some 



10 Shock of extreme intensity . Great disaster; ruins; disturbance 
of the strata, fissures in the ground, rock falls from 
mountains. 



* Although the convention is to use Roman numerals for intensity, in this 
report we have employed arabic characters on the map and thus have adopted 
them in the text. 



-157- 



MODIFIED MERCALLI INTENSITY SCALE 



A need for a more refined scale increased with the advancement of the 
science of seismology, and in 1902 the Italian seismologist, Mercalli, devised 
a new scale on a I to XII range. The Mercalli scale was modified in 1931 by 
American seismologists Harry 0. Wood and Frank Neumann to take into account 
modern structural features. The Modified Mercalli (MM) scale reads as follows: 

I Not felt except by a very few under especially favorable 
circumstances. 

II Felt only by a few persons at rest, especially on upper floors on 
buildings. Delicately suspended objects may swing. 

Ill Felt quite noticeably indoors, especially on upper floors of 
buildings, but many people do not recognize it as an earthquake. 
Standing motor cars may rock slightly. Vibration like passing of 
truck. Duration estimated. 

IV During the day felt indoors by many, outdoors by few. At night, some 

awakened. Dishes, windows, doors disturbed; walls make cracking 

sound. Sensation like heavy truck striking building. Standing motor 
cars rocked noticeably. 

V Felt by nearly everyone, many awakened. Some dishes, windows, etc., 
broken; a few instances of cracked plaster; unstable objects 
overturned. Disturbances of trees, poles and other tall objects 
sometimes noticed. Pendulum clocks may stop. 

VI Felt by all, many frightened and run outdoors. Some heavy furniture 
moved; a few instances of fallen plaster or damaged chimneys. Damage 
slight. 

VII Everybody runs outdoors. Damage negligible in building of good 
design and construction; slight to moderate in well-built ordinary 
structures; considerable in poorly built or badly designed 
structures; some chimneys broken. Noticed by persons driving motor 
cars. 

VIII Damage slight in specially designed structures; considerable in 
ordinary substantial buildings, with partial collapse; great in 
poorly built structures. Panel walls thrown out of frame struc- 
tures. Fall of chimneys, factory stacks, columns, monuments, walls. 
Heavy furniture overturned. Sand and mud ejected in small amounts. 
Changes in well water. Persons driving motor cars disturbed. 

IX Damage considerable in specially designed structures; well-designed 
frame structures thrown out of plumb; great in substantial buildings, 
with partial collapse. Buildings shifted off foundations. Ground 
cracked conspicuously. Underground pipes broken. 



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X Some well-built wooden structures destroyed; most masonry and frame 
structures destroyed with foundations; ground badly cracked. Rails 
bent. Landslides considerable from river banks and steep slopes. 
Shifted sand and mud. Water splashed (slopped) over banks. 

XI Few, if any, (masonry) structures remain standing. Bridges 
destroyed. Broad fissures in ground. Underground pipelines 
completely out of service. Earth slumps and land slips in soft 
ground. Rails bent greatly. 

XII Damage total. Practically all works of construction are damaged 
greatly or destroyed. Waves seen on ground surface. Lines of 
sight and level are distorted. Objects are thrown upward into the 
air. 

The Modified Mercalli intensity scale measures the intensity of an 
earthquake's effects in a given locality, and is perhaps much more meaningful 
to the layman because it is based on actual observations of earthquake effects 
at specific places. It should be noted that because the data used for 
assigning intensities can be obtained only from direct firsthand reports, 
considerable time — weeks or months — is sometimes needed before an intensity 
map can be assembled for a particular earthquake. On the Modified Mercalli 
intensity scale, values range from I to XII. The most commonly used adaption 
covers the range of intensity from the conditions of "I — not felt except by 
very few, favorably situated," to "XII — damage total, lines of sight 
disturbed, objects thrown into the air." While an earthquake has only one 
magnitude, it can have many intensities, which decrease with distance from the 
epicenter. 



CORRELATION OF MODIFIED MERCALLI AND ROSSI-FOREL 
SEISMIC INTENSITY SCALES 

To convert from R-F to MM, the following table may be useful: 
R-F 13 5 7.75 8.75 9.5 10 
MM I III IV-V VI VIII IX X-XII 



o*^ s ' 



-159- 



RICHTER MAGNITUDE SCALE 



The Richter magnitude scale, named after Dr. Charles F. Richter, Professor 
Emeritus of the California Institute of Technology, is the scale most commonly 
used, but often misunderstood. On this scale, the earthquake's magnitude is 
expressed in whole numbers and decimals. However, Richter magnitudes can be 
confusing and misleading unless the mathematical basis for the scale is under- 
stood. It is important to recognize that magnitude varies logarithmically 
with the wave amplitude of the quake recorded by the seismograph. Each whole 
number step of magnitude on the scale represents an increase of 10 times in 
the measured wave amplitude of an earthquake. Thus, the amplitude of an 8.3 
magnitude earthquake is not twice as large as a shock of magnitude 4.3, but 
10,000 times as large. 

Richter magnitude can also provide an estimate of the amount of energy 
released during the quake. For every unit increase in magnitude, there is a 
31-fold increase in energy. For the previous example, a magnitude 8.3 earth- 
quake releases almost one million times more energy than one of magnitude A. 3. 

A quake of magnitude 2 on the Richter scale is the smallest quake normally 
felt by humans. Earthquakes with a Richter magnitude of 7 or more are common- 
ly considered to be major. The Richter magnitude scale has no fixed maximum 
or minimum; observations have placed the largest recorded earthquakes in the 
world at about 8.9, and the smallest at -3. Earthquakes with magnitudes smal- 
ler than 2 are called "micro-earthquakes." Richter magnitudes are not used to 
estimate damage. An earthquake in a densely populated area, which results in 
many deaths and considerable damage, may have the same magnitude as an 
earthquake that occurs in a barren remote area, that may do nothing more than 
frighten the wildlife. 



-160- 



Aft 36 \ 

w smut ,