A Caltech Library Service

Inversion of the body waves from the Borrego Mountain earthquake to the source mechanism

Burdick, L. J. and Mellman, George R. (1976) Inversion of the body waves from the Borrego Mountain earthquake to the source mechanism. Bulletin of the Seismological Society of America, 66 (5). pp. 1485-1499. ISSN 0037-1106.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The generalized linear inverse technique has been adapted to the problem of determining an earthquake source model from body-wave data. The technique has been successfully applied to the Borrego Mountain earthquake of April 9, 1968. Synthetic seismograms computed from the resulting model match in close detail the first 25 sec of long-period seismograms from a wide range of azimuths. The main shock source-time function has been determined by a new simultaneous short period-long period deconvolution technique as well as by the inversion technique. The duration and shape of this time function indicate that most of the body-wave energy was radiated from a surface with effective radius of only 8 km. This is much smaller than the total surface rupture length or the length of the aftershock zone. Along with the moment determination of M_o = 11.2 × 10^(25) dyne-cm, this radius implies a high stress drop of about 96 bars. Evidence in the amplitude data indicates that the polarization angle of shear waves is very sensitive to lateral structure.

Item Type:Article
Related URLs:
URLURL TypeDescription
Additional Information:© 1976 Seismological Society of America. Manuscript received February 25, 1976. The authors thank D. V. Helmberger, T. Heaton, and C. Langston for their advice during this study and for critically reading the manuscript. This research was supported by the Advanced Research Projects Agency of the Department of Defense and was monitored by the Air Force Office of Scientific Research under Contract F44620-72-C-0078.
Funding AgencyGrant Number
Advanced Research Projects Agency (ARPA)UNSPECIFIED
Air Force Office of Scientific Research (AFOSR)F44620-72-C-0078
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences2711
Issue or Number:5
Record Number:CaltechAUTHORS:20140917-104646713
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:49778
Deposited By: Tony Diaz
Deposited On:17 Sep 2014 18:47
Last Modified:03 Oct 2019 07:17

Repository Staff Only: item control page