Source Studies in the Near and Far Field

Abstract

A program has been undertaken to examine the seismic source in the near- and far-fields. Near field accelerogram spectra have been analyzed for corner frequency, seismic moment, and stress drop. For the Bear Valley earthquake of June 22, 1973, a stress drop of 300 bars was obtained using Brune's source theory. The data sample, though, was insufficient to determine any empirical relationship between corner frequency and local magnitude and its association with stress drop. In our examination of far-field source spectral characteristics, de-multipathing procedures have been implemented on the PDP-15 interactive graphics system. Three-dimensional computer plots of double couple source spectra have been produced, and are being used in an exhaustive analysis of far-field spectral characteristics as a function of source configuration.

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Document Details

Document Type
Technical Report
Publication Date
Nov 30, 1974
Accession Number
ADA005786

Entities

People

  • David Sun
  • James C. Battis
  • Lawrence S. Turnbull

Organizations

  • Texas Instruments

Tags

DTIC Thesaurus Topics

  • Computers
  • Doppler Effect
  • Earthquakes
  • Far Field
  • Frequency
  • Graphics
  • Group Velocity
  • Interactive Graphics
  • Love Waves
  • Measurement
  • Near Field
  • Radiation
  • Radiation Patterns
  • Rayleigh Waves
  • Standards
  • Surface Waves
  • Waveforms

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Seismology