Accession Number : ADA331462

Title :   Initial Regionalization Efforts for the IMS Seismic Network

Descriptive Note : Scientific rept. no. 3

Corporate Author : MISSION RESEARCH CORP SANTA BARBARA CA

Personal Author(s) : Bottone, Steven ; Fisk, Mark D. ; McCartor, Gary D. ; Carlson, Richard J.

PDF Url : ADA331462

Report Date : 15 MAR 1997

Pagination or Media Count : 51

Abstract : In this report, initial efforts are described to establish regional training sets and region-specific distance corrections, for use in seismic event characterization, for 35 Primary and 51 Auxiliary seismic stations of the International Monitoring System (IMS) network. Seismic data considered include Pn/Lg and Pn/Sn in the 2-4 Hz, 4-6 Hz, and 6-8 Hz bands for 2797 regional events collected over a 16-month period at the Prototype International Data Centre (PIDC). Regional training sets for each station consist of the discriminant values for events above mb 3.5 (to minimize potential contamination by mining blasts), within 20 degrees from the station, and with signal-to-noise ratios greater than 1.5. Empirical distance corrections are computed for and applied to each discriminant in each training set separately. Events in the training sets which are determined to be outliers, using a generalized likelihood ratio test, are removed and the distance corrections are iteratively recomputed. The training sets for each station are then categorized in terms of their utility for experimental evaluation of event characterization capabilities at the PIDC. Last, future planned efforts to continue improving the initial region-specific distance corrections and training sets are described.

Descriptors :   *SEISMIC DATA, *SEISMIC DISCRIMINATION, DATA BASES, MONITORING, SIGNAL TO NOISE RATIO, SEISMIC WAVES, INTERNATIONAL, SEISMOLOGICAL STATIONS.

Subject Categories : Seismology
      Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE