CaltechAUTHORS
  A Caltech Library Service

Imaging the source region of the 2003 San Simeon earthquake within the weak Franciscan subduction complex, central California

Hauksson, Egill and Oppenheimer, David and Brocher, Thomas M. (2004) Imaging the source region of the 2003 San Simeon earthquake within the weak Franciscan subduction complex, central California. Geophysical Research Letters, 31 (20). Art. No. L20607 . ISSN 0094-8276. https://resolver.caltech.edu/CaltechAUTHORS:20130306-152907607

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

1053Kb
[img] Plain Text (Plain text document) - Supplemental Material
See Usage Policy.

3164b
[img] Postscript (Figure S1) - Supplemental Material
See Usage Policy.

3871Kb
[img] Postscript (Figure S2) - Supplemental Material
See Usage Policy.

7Mb
[img] Postscript (Figure S3) - Supplemental Material
See Usage Policy.

2193Kb
[img] Postscript (Figure S4) - Supplemental Material
See Usage Policy.

2143Kb
[img] Postscript (Figure S5) - Supplemental Material
See Usage Policy.

2068Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20130306-152907607

Abstract

Data collected from the 2003 Mw6.5 San Simeon earthquake sequence in central California and a 1986 seismic refraction experiment demonstrate that the weak Franciscan subduction complex suffered brittle failure in a region without significant velocity contrast across a slip plane. Relocated hypocenters suggest a spatial relationship between the seismicity and the Oceanic fault, although blind faulting on a nearby, unknown fault is an equally plausible alternative. The aftershock volume is sandwiched between the Nacimiento and Oceanic faults and is characterized by rocks of low compressional velocity (Vp) abutted to the east and west by rocks of higher Vp. This volume of inferred Franciscan rocks is embedded within the larger Santa Lucia anticline. Pore fluids, whose presence is implied by elevated Vp/Vs values, may locally decrease normal stress and limit the aftershock depth distribution between 3 to 10 km within the hanging wall. The paucity of aftershocks along the mainshock rupture surface may reflect either the absence of a damage zone or an almost complete stress drop within the low Vp or weak rock matrix surrounding the mainshock rupture.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/2004GL021049DOIArticle
http://onlinelibrary.wiley.com/doi/10.1029/2004GL021049/abstractPublisherArticle
ORCID:
AuthorORCID
Hauksson, Egill0000-0002-6834-5051
Oppenheimer, David0000-0002-6569-3640
Additional Information:© 2004 American Geophysical Union. Received 19 July 2004; revised 14 September 2004; accepted 6 October 2004; published 29 October 2004. The NCSN produced the data that were made available at the Northern California Earthquake Data Center. The figures were made using GMT [Wessel and Smith, 1991]. Supported by USGS/NEHRP Grant 04HQGR0052. Contribution # 9100, GPS, Caltech, Pasadena.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NEHRP/USGS04HQGR0052
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences9100
Issue or Number:20
Classification Code:Index terms: 7205 Seismology: Continental crust (1242); 7215 Seismology: Earthquake parameters; 7230 Seismology: Seismicity and seismotectonics
Record Number:CaltechAUTHORS:20130306-152907607
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20130306-152907607
Official Citation:Hauksson, E., D. Oppenheimer, and T. M. Brocher (2004), Imaging the source region of the 2003 San Simeon earthquake within the weak Franciscan subduction complex, central California, Geophys. Res. Lett., 31, L20607, doi:10.1029/2004GL021049.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:37356
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:07 Mar 2013 00:13
Last Modified:20 Feb 2020 22:10

Repository Staff Only: item control page