Accession Number:

ADA220334

Title:

Advanced Computational Techniques in Regional Wave Studies

Descriptive Note:

Final rept. 1 Jul 1987-30 Nov 1989,

Corporate Author:

SAINT LOUIS UNIV MO DEPT OF EARTH AND ATMOSPHERIC SCIENCES

Report Date:

1990-01-03

Pagination or Media Count:

135.0

Abstract:

This study was concerned with developing computational tools that can support research in nuclear monitoring using seismic techniques. The first paper A students guide to and review of moment tensors, provides a general review of moment tensor notation. Special emphasis is taken to relate the excitation due to an arbitrary seismic dipolecouple source to the Greens functions as defined in Computer Programs in Seismology. Sufficient examples are given to test computer programs connecting Mij to other source representations. The next two papers, Ground roll rejection using adaptive phase matched filters and Ground roll rejection using polarization filters demonstrate the use of the tools developed to extract a low amplitude signal hidden within a large amplitude dispersed signal. The first paper uses techniques developed for enhancing surface waves by phase matched filters. The ground roll surface wave is iteratively isolated using the data to define the proper dispersion. Once the ground roll is isolated, it is subtracted from the signal in the frequency domain. The 2nd paper uses the polarization properties of different seismic wave types to isolate the ground roll. This technique requires multi-component detectors to determine the type of polarization of the particle motion. Once the surface wave is isolated, it can be filtered from the data. The final paper, On scaling of intra-continental earthquakes, improves previous work on the spectral scaling of earthquakes in continental interiors. The observed magnitude for North American events agree, within scattering limits, with predictions based on the improved scaling predictions. edc

Subject Categories:

  • Seismology
  • Seismic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE