Source Studies in the Near- and Far

Abstract

Far-field solutions (source mechanism and focal depth) have been obtained for nineteen events in the Sinkiang, China, earthquake swarm of August 1974. Both spectral and ratio-of-events fitting methods were employed. The solutions indicated two kinds of source mechanisms in this swarm: vertical strike-slip and dip-slip with a dip angle of fourty degrees. The results suggested that these events occurred at shallow depths with the estimated source depth varying between 4 km and 14 km. The effective Rayleigh wave attenuation coefficients along several specific travel paths have been determined for the periods of 10 seconds to 50 seconds. The original and a modified version of the Tryggvason's isotropic-source method for the determination of the surface wave attenuation has been formulated and implemented. They were employed to calculate the average Rayleigh wave attenuation coefficients along the travel paths between eastern Kazakh and three array stations and those between the U.S. Nevada test site (NTS) and the three array stations. The results indicated that the attenuation across the Eurasian continent was much higher than that across the North American continent for the period between 20 and 50 seconds.

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Document Details

Document Type
Technical Report
Publication Date
May 31, 1976
Accession Number
ADA033105

Entities

People

  • David Sun

Organizations

  • Texas Instruments

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Coefficients
  • Depth
  • Earth Models
  • Earthquakes
  • Energy
  • Explosions
  • Far Field
  • Frequency
  • Group Velocity
  • Love Waves
  • Observation
  • Radiation
  • Rayleigh Waves
  • Security Protocols
  • Surface Waves
  • Wave Power

Readers

  • Seismology