CaltechAUTHORS
  A Caltech Library Service

Change of apparent segmentation of the San Andreas fault around Parkfield from space geodetic observations across multiple periods

Barbot, Sylvain and Agram, Piyush and De Michele, Marcello (2013) Change of apparent segmentation of the San Andreas fault around Parkfield from space geodetic observations across multiple periods. Journal of Geophysical Research. Solid Earth, 118 (12). pp. 6311-6327. ISSN 2169-9313. http://resolver.caltech.edu/CaltechAUTHORS:20140206-113945398

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

2365Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

1611Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

176Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

216Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

912Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

168Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

1085Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

857Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

929Kb
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

871Kb
[img] Plain Text (Supporting Information) - Supplemental Material
See Usage Policy.

3719b
[img]
Preview
PDF (Supporting Information) - Supplemental Material
See Usage Policy.

392Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20140206-113945398

Abstract

Sequences of earthquakes are commonly represented as a succession of periods of interseismic stress accumulation followed by coseismic and postseismic phases of stress release. Because the recurrence time of large earthquakes is often greater than the available span of space geodetic data, it has been challenging to monitor the evolution of interseismic loading in its entire duration. Here we analyze large data sets of surface deformation at different key episodes around the Cholame, Parkfield and creeping segments of the San Andreas Fault that show evidence of significant deceleration of fault slip during the interseismic period. We compare the average fault slip rates before and after the 2004 Mw6 Parkfield earthquake, in the 1986–2004 and 2006–2012 periods, respectively, avoiding 2 years of postseismic deformation after 2004. Using a combination of GPS data from the Plate Boundary Observatory, the Southern California Earthquake Center Crustal Motion Map and the Bay Area Velocity Unification networks and interferometric synthetic aperture radar from the Advanced Land Observing Satellite (ALOS) and Envisat satellites, we show that the area of coupling at the transition between the Parkfield and Cholame segments appears larger later in the interseismic period than it does earlier on. While strong plate coupling is uniform across the Parkfield and Cholame segments in the 1986–2004 period, creep occurs south of the 2004 epicenter after 2006, making segmentation of the San Andreas Fault south of Parkfield more clearly apparent. These observations indicate that analyses of surface deformation late in the earthquake cycle may overestimate the area of plate coupling. A fault surface creeping much below plate rate may in some case be a region that does not promote earthquake nucleation but rather just be at a slower stage of its evolution. Our analysis also shows signs of large variation of slip velocity above and below plate rate in the creeping segment indicating that cycles of weakening and hardening can also be at play in dominantly aseismic areas.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1002/2013JB010442DOIArticle
http://onlinelibrary.wiley.com/doi/10.1002/2013JB010442/abstractPublisherArticle
Additional Information:© 2013 American Geophysical Union. Received 22 June 2013; revised 19 October 2013; accepted 6 November 2013; published 9 December 2013. P. Agram was supported by the Keck Institute of Space Studies Postdoctoral Fellowship. S. Barbot was funded by the Gordon and Betty Moore Foundation through grant GBMF 423.01 to the Caltech Tectonics Observatory and by grants from the Earth Observatory of Singapore.
Group:Caltech Tectonics Observatory
Funders:
Funding AgencyGrant Number
Keck Institute of Space Studies Postdoctoral FellowshipUNSPECIFIED
Gordon and Betty Moore FoundationGBMF 423.01
Caltech Tectonics ObservatoryUNSPECIFIED
Earth Observatory of SingaporeUNSPECIFIED
Subject Keywords:interseismic deformation; geodetic data; San Andreas Fault
Record Number:CaltechAUTHORS:20140206-113945398
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20140206-113945398
Official Citation:Barbot, S., P. Agram, and M. De Michele (2013), Change of apparent segmentation of the San Andreas fault around Parkfield from space geodetic observations across multiple periods, J. Geophys. Res. Solid Earth, 118, 6311–6327, doi:10.1002/2013JB010442.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:43701
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:07 Feb 2014 15:33
Last Modified:25 Sep 2014 21:49

Repository Staff Only: item control page