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Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production.
Topics: Seismic Data Interpretation, Geophysics
Open source seismic processing softwares provides a low cost alternative to commercial softwares and, with an appropriately directed development, an ability to adapt to the changing research needs. The best known example of such kind is Seismic Unix, a free reflection processing system developed at the Colorado School of Mines. It has been broadly used in research and teaching seismology and also in smaller scale seismic processing industry. Through this paper the seismic Unix was tested for...
Topics: Processing Seismic Data, Open Source Software, Basra province.
For the seismic data with low SNRs, the first arrival automatic picking method is very important but difficult. In the paper, we proposed a new method based on the mutual information in information theory. The mutual information between signals and noises is zeros, thus random noises have less effects on first arrivals pickup. The paper compares the principle of STA/LTA, AIC, fractal dimension of three kinds with the proposed method for seismic data first–break picking method, and at the same...
Topics: Seismic Data, First Arrivals, Pickup, Information Theory, Mutual Information
An entirely analytic single-station surface-wave processor is developed that analyzes long-period seismic records two orders of magnitude faster than real tme on an IBM 360/44 computer. In processing four days of continuous synthetic data the algorithm detected 85% of the 170 signals of S/N = 1/2, with false alarm rate of one per day. A novel detection theory is introduced that exploits the consistency of the azimuthal estimates associated with a sequence of detections. (Author)
Topics: DTIC Archive, Smart, Eugene, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SURFACE...
We have developed a cepstral F-statistic method that attaches statistical significance to peaks in the cepstra of seismic data. These peaks often result from echoes such as depth phases and thus provide a means of identifying possible depth phase candidates. Detections from this method are stacked as a function of their pP-P and sP-P delay times predicted by IASPEI travel-time tables using a modified version of the network stacking method of Murphy et al. (1999). The method detects depth phases...
Topics: DTIC Archive, *SEISMIC DATA, *STATISTICAL ANALYSIS, EARTHQUAKES, GEOLOGICAL SURVEYS, DEPTH,...
The objectives of this work were to: (1) operate, program, and maintain real time and batch processors; (2) provide services to other government agencies and VELA participants; (3) conduct research in seismology; and (4) develop systems to control and process seismic information generated by remote stations in the Expanded VELA Seismic Network. Network development tasks included refining and developing the Detection Processing System (DPS) and completing efforts to make the Network Event...
Topics: DTIC Archive, Blandford, Robert R, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
Six events from the Baikal rift zone occurring from 1971 to 1975 were examined in a seismic discrimination context. Seismograms from ALPA, LASA, NORSAR, the HGLP, the WWSSN, and the SRO stations were studied for source mechanism, Ms-mb, corner frequency, pP, complexity, and spectral ratio. All the Baikal events can be identified as earthquakes except the November 5, 1976, event which shows explosion characteristics. The characteristics of the Baikal events were compared to six East Kazakh...
Topics: DTIC Archive, Sobel, P A, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *NUCLEAR...
Using Jordan and Anderson's earth model B1, we calculated theoretical travel times, depth allowance tables, branch interval times, and B factors for all PKP phases; the results are in tabular form. Travel times are calculated with polynomial approximations, and those coefficients are also computed. New additions to those tables are the data for the CD branch, which are the PKiKP arrivals in the distance range of 109 to 158 deg. Although travel times of the CD branch fall within a few seconds of...
Topics: DTIC Archive, Chang, Andre C, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
Several location methods developed at SDAC are evaluated by comparing location errors of these methods against errors computed with the standard method. The new methods include: Using P travel times in laterally heterogeneous media: A station travel time residual correlation matrix in the normal equations; Location with simultaneous determination of Pn, Pg, and Lg velocities; Combination of the correlation matrix method and the simultaneous determination method. All the methods evaluated in...
Topics: DTIC Archive, Chang,A C, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *Seismic...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
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Aug 13, 2018
08/18
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Adisorn Sridej and Akkhapun Wannakomol
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The objective of this study is to predict formation pore pressure in San Sai oilfield of Fang basin, located in Chiang Mai Province, Northern Thailand, by using seismic data. The main activities in this study were: (1) required data collecting, including seismic travel time data, overburden pressure, and hydrostatic pressure data of San Sai oilfield, (2) normal compaction trend generating from p-wave transit time, and (3) formation pore pressure calculation by using the Eaton’s method of...
Topics: Pore pressure gradient estimation, Seismic data, San Sai oilfield, Fang basin, Northern Thailand
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
This paper introduces a new fully-automated method for identifying clusters in large event sets. The method uses Delaunay tessellation to determine the clusters and initial membership, then applies an iterative K-method optimization to refine membership in the clusters until stability is achieved. The method is robust and computationally efficient, with performance improvement over standard K-method optimization from O(n2) to O(n log n), which is achieved by making use of the Delaunay...
Topics: DTIC Archive, SANDIA NATIONAL LABS ALBUQUERQUE NM, *SEISMIC DATA, *CLUSTERING, SYMPOSIA,...
Analysis of 1,471 P- and PKP-coda indicates that the probability of an unexplained phase occurring in a coda of an event as recorded at a single station is 0.12 for a detection threshold on the order of 3.5db (signal-to-coda background). The average coda length is roughly six minutes (343 seconds) for the events examined. The probability, therefore, that the seismograms at four stations out of thirteen will exhibit unexplained phases in the coda of a given earthquake is 0.045.
Topics: DTIC Archive, Cohen, T J, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The Korean Seismic Research Station (KSRS) short-period array was evaluated using data which cover eight-hour time periods daily between May and June 1973. Most of the data is of poor quality due to instrumental problems. The average noise reduction obtained by beaming was about 2 dB better than square root of (N) due to the almost continuous presence of propagating coherent noise at the station. The 50% detection body wave magnitude threshold was found to be 4.35 + or - .45 (95% confidence...
Topics: DTIC Archive, Blaik, Maurice, Der, Zoltan, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS...
Eight earthquakes from the Caucasus occurring from 1971 to 1975 were examined in a seismic discrimination context. Seismograms from ALPA, LASA, NORSAR, and the HGLP and the WWSSN stations were studied for source mechanism, (M sub s - M sub b), corner frequency, pP, complexity, and spectral ratio. All the Caucasus events can be identified as earthquakes by means of pP and M sub s:M sub b when compared to Kazakh and southwest USSR explosions. However it seems plausible that these discriminants...
Topics: DTIC Archive, Sobel, P A, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The operation and maintenance of the Seismic Data Analysis Center (SDAC) are summarized for the contract year beginning 1 October 1978 and ending 30 September 1979. Reported are the statistics relating to computer usage; information relating to the maintenance, programming, data services, data availability; and the effort to expand the research systems at the facility. This final report summarizes the operation and maintenance of the computer systems at the Seismic Data Analysis Center (SDAC)...
Topics: DTIC Archive, Kovacs, Paul, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
This is the third report in a series of three published at the Seismic Data Analysis Center in 1974, which describe studies of and programming experience with the ILLIAC IV computer. The present report is a computer listing of the ILLIAC IV version of a scientific program called FKCOMB. The main program, FKCOMB, and two data-editing and formatting modules, DEM1 and DEM2 were written in Computational Fluid Dynamics Code (CFD); some subroutines were written in ASK code.
Topics: DTIC Archive, Kerr, Ann, Wagenbreth, Gene, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS...
The SRO station MAIO was used to obtain many measurements of P sub and LR from a sequence of aftershocks at Gazli, Uzbekistan in 1976, at a distance of 576 km. SP periods and amplitudes are analyzed to obtain the proper distance correction factor to yield m sub b. Eighteen events are measured to give an M sub s range 2.2 to 3.6, and m sub b range 3.6 to 5.0. The observations support the postulation that delta M sub s/delta M sub b is approximately equal 1 to at low magnitudes. The Gazli...
Topics: DTIC Archive, Goncz, John H, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
Eleven earthquakes with low reported M sub s for their m sub b from the Northern Pamirs were examined in a seismic discrimination context. Seismograms from ALPA, LASA, NORSAR, the HGLP and the WWSSN stations were studied for source mechanism, M sub s-m sub b, corner frequency, pP, complexity, and spectral ratio. All the Parmir events can be identified as earthquakes when their characteristics are compared to those of Kazakh explosions. P-waves to NORSAR from these earthquakes exhibit very high...
Topics: DTIC Archive, Sobel, P A, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
Measurements of log(A/T) reported by the International Seismic Centre, the Vela Observatories, and the Long-Range Seismic Measurements Program are used to define an amplitude-distance curve for the maximum amplitude in the first few seconds of motion for the distance range delta 90 degrees. In general terms, the corresponding phases are P, P(diff), and PKIKP. Some information is also obtained, however, for the phases PP and PKP2.
Topics: DTIC Archive, Sweetser, E I, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The resolution in A/D conversion when recording waveforms of night- time (low) noise on four different NSS channels at CPO is 0.3 to 1% of the RMS noise power. Clipping of the middle period (MP) and long period (LP) channels in A/D conversion was observed in the case of an M sub s = 7.6 shock at a distance 22 deg, and signal amplitudes up to 30% of the clipping level were observed on the short-period channel when recording nondestructive local shocks (up to 1 deg). In one such case a probably...
Topics: DTIC Archive, Noponen, I T, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
The report summarizes the technical work, support, effort, and data services completed during the Quarter January through March 1974. The report is organized into Part A describing Operations and Maintenance functions (Tasks 1 through 4) and Part B describing Research (Tasks 5 through 8). Part B describes only work represented by completed technical reports. Part C is a summary of the energy conservation measures taken at the SDAC and some early results of those measures. Part D is a review of...
Topics: DTIC Archive, Hartenberger, Royal A, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
Re-analysis of SALMON and STERLING initial short-period compressional and surface waves at station PLMS (Poplarville, Mississippi) at a distance of 27 km shows a SALMON/STERLING compressional phase spectral ratio tending to a ratio of only 17 at 25 Hz in agreement with the theoretical caculations of Patterson (1966) and of Healy, King, and 0'Neill (1971). The spectral ratio for the surface waves tends to a ratio of approximately 100 at 25 Hz, in agreement with spectral ratios previously...
Topics: DTIC Archive, Blandford, Robert R, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
In the second year of this project, the main objective continues to be the formation of databases providing ground truth for regional seismic research conforming to the latest Center for Monitoring Research (CMR) schema. The effort focuses on events in the CMR Calibration Event Bulletin (CEB) from China, the former Soviet Union, and North America. Selected CEB events are re-analyzed using the seismic analysis software geotool starting with the Reviewed Event Bulletin (REB) solutions....
Topics: DTIC Archive, MULTIMAX INC HERNDON VA, *SEISMIC DATA, *DATA BASES, SURFACE TRUTH, SYMPOSIA,...
This report presents a collection of small and large earthquake short-period coda shapes as a function of distance. It is summarized from previous studies by Cohen, Sweetser, and others. New results include coda shapes for delta 20 deg. The report is intended to serve as a reference for workers who investigate problems related to hiding an explosion in an earthquake. A detailed examination of earthquake and explosion coda also shows for delta 20 deg that the amplitude ratio P(sub g)/L(sub g)...
Topics: DTIC Archive, Blandford, Robert, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
A Consortium of institutions which includes Maxwell Technologies, Inc., Massachusetts Institute of Technology's Earth Resources Laboratory (ERL), Weston Geophysical Corporation, the Russian Institute for Dynamics of the Geospheres (IDG), the Department of Geophysics of Peking University, and the Seismological Bureau of Sichuan Province has been assembled to conduct a research program directed toward the seismic travel time calibration of the 30 Group 1 IMS stations of eastern Asia. A carefully...
Topics: DTIC Archive, MAXWELL TECHNOLOGIES INC SAN DIEGO CA, *SEISMIC DATA, SEISMOLOGICAL STATIONS, ASIA,...
LASA subarray amplitude anomalies are investigated using 395 medium- sized events, distributed in ten azimuthally divided sectors. Although LASA magnitudes, when averaged over all azimuths, are only slightly biased relative to NEIS magnitudes, the amount of bias varies with azimuth and subarray, suggesting that a simple station correction for m sub b bias is not adequate. In addition, fluctuations among LASA subarrays are about 0.15 in standard deviation, even when these magnitudes are...
Topics: DTIC Archive, Chang, A C, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *DATA...
This report contains seismic data from the Special Data Collection System (SDCS) and other sources for the Northeastern China, 27 July 1976, event. Published epicenter information from seismic observations is provided. Using SDCS stations, LASA and NORSAR, the epicenter location and magnitudes become: Origin time -- 19:42:48.9; Latitude -- 38.8N; Longitude -- 117.6E; and M sub B - - 6.6.
Topics: DTIC Archive, Dawkins, M S, TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS, *SEISMIC DATA, CHINA,...
The Source Physics Experiment (SPE-N) at the Nevada National Security Site (NNSS) is planned as a series of chemical explosions under a variety of emplacement conditions. The SPE-N goal is to improve our physical understanding and ability to model how explosion generate seismic waves, particularly S-waves. The first SPE-N explosion (SPE1) occurred in May 2011 and consisted of a 220 lb (100 kg) chemical explosion at a depth of 180 ft (55 m) in granite (Climax Stock). This paper examines the...
Topics: DTIC Archive, LAWRENCE LIVERMORE NATIONAL LAB CA, *EXPLOSIONS, FAR FIELD, PHYSICS, SEISMIC DATA,...
Production of high-quality data sets for calibration of seismic travel times remains a painstaking and costly endeavor. The value of meticulous data analysis is beyond reproach, but the number and coverage of events with accurate locations and carefully measured seismic-phase arrival times is not sufficient for either development of high-fidelity (3-dimensional) models or comprehensive empirical calibration. Although regional and global bulletins of seismic data provide excellent data coverage,...
Topics: DTIC Archive, LAWRENCE LIVERMORE NATIONAL LAB CA, *SEISMIC DATA, CALIBRATION, DATA BASES, SPURIOUS...
Automatic seismogram interpretation and onset estimation are desirable goals facilitating the rapid location and discrimination of seismic events, automation also relieves the human operator from onerous repetitive tasks. At regional distances the onsets of seismic phases are associated with gradual, rather than sudden, changes in the statistical properties of the seismic time series, i.e. changes in autoregressive models and mean square amplitudes. The work presented combines two aspects of...
Topics: DTIC Archive, ENSCO INC SPRINGFIELD VA, *AUTOMATION, *STATISTICAL ANALYSIS, *SEISMIC DATA,...
Although it permits more rapid seismic data processing than before being implemented, the Network Event Processing (NEP) system at the Seismic Data Analysis Center could still perform more routine analysis tasks automatically. This report discusses these tasks, including: identification of false alarms in detection lists, timing of P and LR/LQ arrivals, associating seismic arrivals to events, depth-of-focus estimation, and measurement of magnitude. Approaches to automating these tasks are...
Topics: DTIC Archive, von Seggern, D H, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *DATA...
Spall signals, if present on teleseisms, should be most easily detected in the short-period P-waveforms. If pP and spall (P sub s) echoes are identical in waveform to the P then, theoretically, deghosting filters could remove these source echoes and produce identical seismograms from neighboring explosions with nearly identical source-to-receiver paths. If P sub s is absent, the pP corrections alone suffice. Determining the optimum echo amplitude and delay parameters involves trial-and-error...
Topics: DTIC Archive, Dean, William C., TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
This report contains seismic data from the Special Data Collection System (SDCS) and other sources for the Eastern Kazakh SSR, 4 July 1976, event. Published epicenter information from seismic observations is provided. Using SDCS stations, LASA and NORSAR, the epicenter location and magnitudes become: Origin time -- 02:57:02.2; Latitude -- 50.2 N; Longitude -- 078.6 E m sub b 5.8; and m sub s 3.9.
Topics: DTIC Archive, Dawkins, M S, TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS, *SEISMIC DATA,...
This report contains seismic data from the Special Data Collection System (SDCS) and other sources for the Western Kazakh SSR, 29 July 1976, event. Published epicenter information from seismic observations is provided. Using SDCS stations, LASA and NORSAR, the epicenter location and magnitudes become: Origin time -- 05:00:08.5; Latitude -- 49.1N; Longitude -- 047.7E; and m sub b 6.3.
Topics: DTIC Archive, Dawkins, M S, TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS, *SEISMIC DATA,...
This report contains seismic data from the Special Data Collection System (SDCS) and other sources for the Eastern Kazakh SSR, 23 July 1976, event. Published epicenter information from seismic observations is provided. Using SDCS stations, LASA and NORSAR, the epicenter location and magnitudes become: Origin time -- 02:33:01.2; Latitude -- 50.1N; Longitude -- 77.7E; and m sub b -- 4.8.
Topics: DTIC Archive, Dawkins, M S, TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS, *SEISMIC DATA,...
Two features of the ILLIAC IV system at NASA/Ames are particularly appropriate to the processing of seismic data. One is its ability to apply a given algorithm to sixty-four different data streams simultaneously, thus providing an order of magnitude increase in processing speed over conventional machines. The second is its large data storage. The seismological algorithms for convolution filtering, beamforming, matched filtering, PHILTRE, maximum likelihood, and FKCOMB are each able to take...
Topics: DTIC Archive, Kerr, Ann, Wagenbreth, Gene, Smatt, Eugene, Der, Zoltan, TELEDYNE GEOTECH ALEXANDRIA...
This report provides information and statistics concerning the operation and maintenance of the computer systems at the SDAC, a consideration of the abstracts from the technical reports resulting from studies and seismic research, and a summary of the work accomplished to expand the computer systems and programs used for the VELA Network.
Topics: DTIC Archive, Blandford, Robert R, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER,...
A new set of region corrections has been generated for LASA which more adequately covers the seismically active area of the earth than did previous sets. The new set contains 183 calibration nodes versus 105 nodes on the set used in the SDAC/LASA system throughout 1972 and the first half of 1973. Each mode contains the average relative travel-time anomalies for each of the 21 subarrays at LASA which are valid over an area surrounding the location of the node. The corrections were generated from...
Topics: DTIC Archive, Chiburis, E F, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *SEISMIC...
Our research group is collecting and analyzing various levels of high-resolution seismic data and cores, for ground-truthing seismic facies, on continental margins with a spectrum of depositional boundary conditions. The long-term goal of this work is develop stochastic models of variation of geotechnical and seismic property distribution on margins subjected to a spectrum of depositional regimes. The product of this research is are models of continental margins that show the probability of...
Topics: DTIC Archive, NORTH CAROLINA UNIV AT CHAPEL HILL, *SEISMOLOGY, GEOLOGY, OCEAN BOTTOM, PROBABILITY,...
Seismic event locations obtained by using P sub g and P sub n arrivals may cause severe errors because the Earth's crust is laterally heterogeneous. Location errors are attributed to the fact that crustal velocities and thicknesses for each source-to-station path are different from those of the standard crustal model used in the location program. To overcome this difficulty, we have installed a number of crustal models in a location program and made it possible for each station to be assigned...
Topics: DTIC Archive, Chang, A C, TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA ANALYSIS CENTER, *ACCURACY,...
