|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Short Note |
Department of Geological and Atmospheric Sciences
Iowa State
University
253 Science I
Ames, Iowa
50011-3212
beresnev{at}iastate.edu
Earthquake sources are commonly viewed as shear dislocations. This imposes distinct limitations on what source parameters can be realistically determined from radiated shear-wave spectra. First, the slip velocity on the fault is the real parameter that controls the strength of the high-frequency radiation; it can be directly determined from acceleration spectra by fitting their high-frequency level. Second, the relationship between corner frequency of the spectrum and the radius of the source is fundamentally unclear. As a result, the source dimensions cannot be accurately determined from the spectra; such an estimate would be as accurate as any other informed guess. Third, the stress drop only serves as a proxy for the source radius in the relationship between the radius and the corner frequency; it thus cannot be reliably determined from the spectra. The quantity usually obtained from the spectra and referred to as the stress drop is a poorly defined parameter that may bear little relevance to the actual stresses acting on faults. This parameter has little meaning unless converted to the maximum slip velocity, which is the only quantity that can be accurately determined from the spectra. The typical value of stress drop of 100 bars, established from the spectra of California events, may imply that the typical slip velocities have been on the order of 0.5 m/sec, although it is more accurate to determine slip velocities directly from the spectra.
This article has been cited by other articles:
|
|
 |
|
  N. A. Anil-Bayrak and I. A. Beresnev Fault Slip Velocities Inferred from the Spectra of Ground Motions Bulletin of the Seismological Society of America, April 1, 2009; 99(2A): 876 - 883. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Oth, S. Parolai, D. Bindi, and F. Wenzel Source Spectra and Site Response from S Waves of Intermediate-Depth Vrancea, Romania, Earthquakes Bulletin of the Seismological Society of America, February 1, 2009; 99(1): 235 - 254. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Bose, F. Wenzel, and M. Erdik PreSEIS: A Neural Network-Based Approach to Earthquake Early Warning for Finite Faults Bulletin of the Seismological Society of America, February 1, 2008; 98(1): 366 - 382. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Tusa, A. Brancato, and S. Gresta Source Parameters of Microearthquakes in Southeastern Sicily, Italy Bulletin of the Seismological Society of America, June 1, 2006; 96(3): 968 - 983. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Sokolov, K.-P. Bonjer, M. Oncescu, and M. Rizescu Hard Rock Spectral Models for Intermediate-Depth Vrancea, Romania, Earthquakes Bulletin of the Seismological Society of America, October 1, 2005; 95(5): 1749 - 1765. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Source Parameters Observable from the Corner Frequency of Earthquake Spectra Bulletin of the Seismological Society of America, June 1, 2002; 92(5): 2047 - 2048.
|
|
|
|
|
|
Source Parameters of Earthquakes in Eastern and Western North America Based on Finite-Fault Modeling Bulletin of the Seismological Society of America, March 1, 2002; 92(2): 695 - 710.
|
|
|
|
 |
|
 B. Stockhert Stress and deformation in subduction zones: insight from the record of exhumed metamorphic rocks Geological Society, London, Special Publications, January 1, 2002; 200(1): 255 - 274. [Abstract] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
