CaltechAUTHORS
  A Caltech Library Service

The effect of crustal structure on strong ground motion attenuation relations in eastern North America

Burger, R. W. and Somerville, P. G. and Barker, J. S. and Herrmann, R. B. and Helmberger, D. V. (1987) The effect of crustal structure on strong ground motion attenuation relations in eastern North America. Bulletin of the Seismological Society of America, 77 (2). pp. 420-439. ISSN 0037-1106. https://resolver.caltech.edu/CaltechAUTHORS:20140902-143830541

[img]
Preview
PDF - Published Version
See Usage Policy.

855Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20140902-143830541

Abstract

Strong ground motion attenuation relations are usually described by smoothly decreasing functions of distance. However, consideration of wave propagation in the crust suggests that attenuation relations should be more complex. Such complexity may be present in strong ground motion data for eastern North American earthquakes, which show amplitudes in the distance range of 60 to 150 km that lie above the trends at smaller and greater distances. Using a wavenumber integration method to compute Green's functions and close-in recordings of several earthquakes as empirical source functions, we have generated synthetic seismograms that are in good agreement with regional and strong-motion recordings of eastern North American earthquakes. From these synthetic seismograms, we have shown that the observed interval of relatively high amplitudes may be attributable to postcritically reflected S waves from the Moho. The presence and location of the interval of relatively high amplitudes is highly dependent on the crustal velocity structure and may therefore be expected to show regional variation. However, for any realistic structure model, there will be a transition in the attenuation relation from an interval at shorter distances (less than about 100 km) that is dominated by direct waves to an interval at greater distances that is dominated by postcritically reflected waves. The synthetic seismograms have response spectral velocities that match those of the recorded data, and their m_(bLg) values are in good agreement with observed values.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://bssa.geoscienceworld.org/content/77/2/420.abstractPublisherArticle
Additional Information:© 1987, by the Seismological Society of America. Manuscript received 19 February 1986. The authors thank C. B. Crouse and the anonymous reviewer for their comments. We are very grateful to R. Halliday and W. Shannon of the Earth Physics Branch of the Energy, Mines and Resources of Canada for providing seismograms. This study was sponsored by the Electric Power Research Institute.
Funders:
Funding AgencyGrant Number
Electric Power Research InstituteUNSPECIFIED
Issue or Number:2
Record Number:CaltechAUTHORS:20140902-143830541
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20140902-143830541
Official Citation: R. W. Burger, P. G. Somerville, J. S. Barker, R. B. Herrmann, and D. V. Helmberger The effect of crustal structure on strong ground motion attenuation relations in eastern North America Bulletin of the Seismological Society of America, April 1987, v. 77, p. 420-439
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:49144
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:02 Sep 2014 21:49
Last Modified:03 Oct 2019 07:11

Repository Staff Only: item control page