High-Frequency P Wave Spectra from Explosions and Earthquakes

  1. Steven R. Taylor,
  2. Howard J. Patton and
  3. Paul G. Richards
  1. William R. Walter and
  2. Keith F. Priestley

Published Online: 18 MAR 2013

DOI: 10.1029/GM065p0219

Explosion Source Phenomenology

Explosion Source Phenomenology

How to Cite

Walter, W. R. and Priestley, K. F. (1991) High-Frequency P Wave Spectra from Explosions and Earthquakes, in Explosion Source Phenomenology (eds S. R. Taylor, H. J. Patton and P. G. Richards), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM065p0219

Author Information

  1. Seismological Laboratory, Mackay School of Mines, University of Nevada, Reno, Nevada 89557

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1991

ISBN Information

Print ISBN: 9780875900315

Online ISBN: 9781118663820

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Keywords:

  • Underground nuclear explosions—Detection—Congresses;
  • Seismology—Congresses

Summary

Two explosion P wave spectral models [Sharpe, 1942; Mueller-Murphy, 1971] and two earthquake P wave spectral models [Archambeau, 1968, 1972; modified Brune 1970, 1971] are reviewed to assess their implications for high-frequency (>1 Hz) seismic discrimination between earthquakes and explosions. The importance of the corner frequency scaling, particularly for models with the same high-frequency spectral decay rate, is demonstrated by calculating source spectral ratios (a potentially important regional discriminant) for these models. We compare North American events and a limited data set of Central Asian events with these spectral models. We find North American earthquakes are consistent with a constant stress drop modified Brune model between 10 and 30 Hz. Shallow (<700 m depth) Pahute Mesa explosions at the Nevada Test Site have a high-frequency spectral decay between 10 and 30 Hz greater than the ω−2 predicted by the explosion models. Near regional recordings of the Soviet Joint Verification Experiment (JVE) explosion show a higher corner frequency and lower 1 to 4 Hz spectral ratios than predicted by either explosion model. The higher corner frequency of the Soviet JVE appears not to be due to attenuation, or receiver effects, and may represent a need for different corner frequency scaling, or result from source complications such as spall and tectonic release. A regional recording of the Soviet JVE (NEIC mb = 6.1) is shown to have a lower 1 to 4 Hz spectral ratio than a smaller earthquake (NEIC mb = 4.6) recorded on a nearly reciprocal path.