Accession Number : ADA338843

Title :   The Application of Broadband Arrays and Networks to Seismic Monitoring of Uncalibrated Regions

Descriptive Note : Final rept. 1 Jul 94-30 Jun 97

Corporate Author : SOUTH CAROLINA UNIV COLUMBIA DEPT OF GEOLOGY

Personal Author(s) : Owens, Thomas J.

PDF Url : ADA338843

Report Date : 30 NOV 1997

Pagination or Media Count : 7

Abstract : Temporary broadband networks are clearly an advantage to efforts to calibrate relatively unknown regions. Our results demonstrate the type of information that can be determined with this type of data. Students have participated in this effort supported by both the Parent Agreement and the AASERT supplement. AASERT funding has been the primary support for Ph.D. student Philip Crotwell, who is working on the Sn propagation studies outlined below. The discrimination studies have been the focus of research by MS student Mark Powers, supported on the Parent Agreement. The Lg study was undertaken by Ph.D. student Dan McNamara with salary support from other sources, but computing, travel and publication support from the Parent Agreement. Our Lg results have clarified a long-standing debate about the cause of Lg blockage by the Tibetan Plateau. Understanding the nature of this blockage is critical to understanding the effect it has on common discriminants that utilize Lg. The unusual propagation characteristics of Sn also lead to anomalous waveforms that need to be understood before regional waveforms from this area can be confidently used for seismic monitoring measurements. Continuing regional waveform modeling has led to a better understanding of north-south variations in mantle structure and the effects these variations have on regional waveforms. We have also been able to better quantify the effect of event mislocation on derived layered velocity models in the Tibetan Plateau. In addition, using the sources and structural information derived in our work, we will be compiling common discriminant measurements for many regional events in the plateau to better document the influence the unusual regional structure may have on event discrimination in Central Asia. We have completed the determination of a local magnitude scale for events recorded by the 1991-92 Tibetan Pla

Descriptors :   *SEISMIC DATA, MONITORING, WAVEFORMS, SEISMIC DETECTION, BROADBAND, ASIA, DISCRIMINATE ANALYSIS, PRIMARY WAVES(SEISMIC WAVES), SEISMIC ARRAYS.

Subject Categories : Geology, Geochemistry and Mineralogy
      Seismology

Distribution Statement : APPROVED FOR PUBLIC RELEASE