A Caltech Library Service

The Seismogenic Thickness of the Southern California Crust

Nazareth, Julie J. and Hauksson, Egill (2004) The Seismogenic Thickness of the Southern California Crust. Bulletin of the Seismological Society of America, 94 (3). pp. 940-960. ISSN 0037-1106.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The average seismogenic thickness, measured from the surface down to maximum depth of earthquake rupture, for the southern California crust is 15.0 km (+1.2/–1.1 km). We determine the seismogenic thickness using the depth distribution of the seismic moment release of ∼19 years of seismicity. We calibrate the depth distribution of moment release from background seismicity by comparing the maximum depth of rupture during moderate- to large-magnitude earthquakes to the premainshock background seismicity of the respective mainshock region. The calibration shows that the depth above which 99.9% of the moment release of background seismicity occurs reliably estimates the maximum depth of rupture during moderate to large earthquakes. Locally, the seismogenic thickness is highly variable, ranging from less than 10 km in the Salton Trough to greater than 25 km at the southwestern edge of the San Joaquin Valley. Similarly, the seismogenic thickness along the major strike-slip faults can vary significantly along strike. Changes in seismogenic thickness along strike do not correspond to the mapped surface segmentation of the major southern California strike-slip fault systems. In the future, such estimates of the seismogenic thickness can be used to refine existing seismic-hazard estimates for southern California.

Item Type:Article
Related URLs:
URLURL TypeDescription
Hauksson, Egill0000-0002-6834-5051
Additional Information: © 2004 Seismological Society of America. Manuscript received 17 June 2002. We thank R. Clayton and N. Field for interest in this project and important discussions, and Jeanne Hardebeck, Harold Magistrale, and Keith Richards-Dinger for reviewing the manuscript. Their comments greatly improved the manuscript. The figures were done using GMT (Wessel and Smith, 1991). This work was supported by U.S. Geological Survey Grants 01HQGR038 and 02HQGR0044 to Caltech and by grants from the Southern California Earthquake Center. SCEC is funded by National Science Foundation Cooperative Agreement EAR-0106924 and USGS Cooperative Agreement 02HQAG0008. This article is SCEC contribution no. 753. It is contribution 9031, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California.
Group:Seismological Laboratory, Division of Geological and Planetary Sciences
Funding AgencyGrant Number
Southern California Earthquake Center (SCEC)UNSPECIFIED
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Southern California Earthquake Center (SCEC)753
Caltech Division of Geological and Planetary Sciences9031
Issue or Number:3
Record Number:CaltechAUTHORS:20130227-135533636
Persistent URL:
Official Citation:Julie J. Nazareth and Egill Hauksson The Seismogenic Thickness of the Southern California Crust Bulletin of the Seismological Society of America, June 2004, v. 94, p. 940-960, doi:10.1785/0120020129
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:37182
Deposited By: Ruth Sustaita
Deposited On:28 Feb 2013 15:55
Last Modified:03 Oct 2019 04:45

Repository Staff Only: item control page