Accession Number : ADA317380

Title :   Regional Attenuation at GSETT-3 Stations and the Transportability of the Lg/P Discriminant.

Descriptive Note : Scientific rept. no. 1,

Corporate Author : SCIENCE APPLICATIONS INTERNATIONAL CORP SAN DIEGO CA

Personal Author(s) : Jenkins, Richard D. ; Velasco, Aaron A. ; Williams, Donna J. ; Sereno, Thomas J., Jr

PDF Url : ADA317380

Report Date : 15 JUL 1996

Pagination or Media Count : 42

Abstract : Recent studies have shown that the high-frequency Lg/P ratio can be an effective discriminant at regional distances. However, this ratio must be recalibrated for each new source region. We are developing regional wave attenuation models for up to 10 subnetworks of the International Data center (IDC) primary network, and will use them to evaluate the transportability of the Lg/P discriminant to uncalibrated regions. We are measuring amplitudes of regional phases in the time and frequency domain, and using our new software program, AmpInv, to invert for source and attenuation models. During the first year of this two-year project we developed all software needed for this study, investigated alternative amplitude measures, and compiled a data set for an Australian subnetwork. During the second year we will compile the data sets for the other IDC subnetworks, estimate regional wave attenuation using AmpInv, and evaluate the accuracy and transportability of the Lg/P discriminant. We will also obtain 'ground-truth' identification for as many of the events as possible, and we will use knowledge of the local natural and industrial seismicity when this information is not available.

Descriptors :   *SEISMIC DISCRIMINATION, DATA BASES, ATTENUATION, CALIBRATION, TIME DOMAIN, FREQUENCY DOMAIN, DISCRIMINATE ANALYSIS, SURFACE TRUTH.

Subject Categories : Seismology

Distribution Statement : APPROVED FOR PUBLIC RELEASE