Accession Number : ADP204486

Title :   Characterization of Seismic Source Using Short-Period Seismic Waves,

Corporate Author : CALIFORNIA UNIV SANTA CRUZ

Personal Author(s) : Zhang, Jiajun

PDF Url : ADP204486

Report Date : 14 AUG 1995

Pagination or Media Count : 8

Abstract : A new algorithm is proposed for the reduction of the complexity of observed seismic waves in the 1-100 sec period band. The algorithm transforms the waveform for an event into a simplified form and is referred to as the Earth simplifying transformation (EST). The event is referred to as the primary event, for which properties of the source are to be determined. The EST algorithm uses data and synthetics for another event nearby, which is referred to as the secondary event. The synthetics are computed for a given Earth model using a priori source parameters for the secondary event. Data for the algorithm are regional or teleseismic seismograms, including surface waves and/or body waves. In this algorithm, data for the primary event are deconvolved with the residual waveform which is obtained from the deconvolution of data and synthetics for the secondary event. The residual waveform contains the effects of Earth's structure on seismic waves which are not predicted for the Earth model. The simplified waveform obtained from the algorithm is referred to as the EST seismograms. The EST seismogram represents the waveform which is expected for the seismic waves from the primary event for the Earth model. The source properties for the primary event can be determined from EST seismograms instead of original data, which contain not only the information on the source but also the effects of Earth's structure unpredictable for the model. Several tests were made using data from earthquakes located in southern California recorded at Global Seismographic Network (GSN) stations, with the distance between the primary and secondary events being less than 100 km. These tests indi cate that EST seismograms provide superior resolution power in the source characterization than original seismograms.

Descriptors :   *SEISMIC DETECTION, *SEISMIC WAVES, *ARMS CONTROL, *NUCLEAR EXPLOSION DETECTION, *EARTHQUAKES, ALGORITHMS, SYMPOSIA, SURFACE WAVES, VERIFICATION, MONITORING, UNDERGROUND EXPLOSIONS, NUCLEAR EXPLOSION TESTING, GROUND MOTION, SEISMIC DATA, CALIFORNIA, SEISMIC DISCRIMINATION, TREATIES, EARTH MODELS, PRIMARY WAVES(SEISMIC WAVES), SEISMOLOGICAL STATIONS, SEISMOGRAPHS.

Subject Categories : Government and Political Science
      Seismology
      Seismic Detection and Detectors
      Nuclear Weapons

Distribution Statement : APPROVED FOR PUBLIC RELEASE