• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Geology and Geophysics (G&G)
    • View Item
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Geology and Geophysics (G&G)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of WHOASCommunities & CollectionsBy Issue DateAuthorsTitlesKeywordsThis CollectionBy Issue DateAuthorsTitlesKeywords

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Relationships among seismic velocity, metamorphism, and seismic and aseismic fault slip in the Salton Sea Geothermal Field region

    Thumbnail
    View/Open
    Article (5.637Mb)
    Figures S1 and S2 (587.7Kb)
    Date
    2015-04-28
    Author
    McGuire, Jeffrey J.  Concept link
    Lohman, Rowena B.  Concept link
    Catchings, Rufus D.  Concept link
    Rymer, Michael J.  Concept link
    Goldman, Mark R.  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/7335
    As published
    https://doi.org/10.1002/2014JB011579
    DOI
    10.1002/2014JB011579
    Keyword
     Geothermal field; Earthquakes; Fault creep 
    Abstract
    The Salton Sea Geothermal Field is one of the most geothermally and seismically active areas in California and presents an opportunity to study the effect of high-temperature metamorphism on the properties of seismogenic faults. The area includes numerous active tectonic faults that have recently been imaged with active source seismic reflection and refraction. We utilize the active source surveys, along with the abundant microseismicity data from a dense borehole seismic network, to image the 3-D variations in seismic velocity in the upper 5 km of the crust. There are strong velocity variations, up to ~30%, that correlate spatially with the distribution of shallow heat flow patterns. The combination of hydrothermal circulation and high-temperature contact metamorphism has significantly altered the shallow sandstone sedimentary layers within the geothermal field to denser, more feldspathic, rock with higher P wave velocity, as is seen in the numerous exploration wells within the field. This alteration appears to have a first-order effect on the frictional stability of shallow faults. In 2005, a large earthquake swarm and deformation event occurred. Analysis of interferometric synthetic aperture radar data and earthquake relocations indicates that the shallow aseismic fault creep that occurred in 2005 was localized on the Kalin fault system that lies just outside the region of high-temperature metamorphism. In contrast, the earthquake swarm, which includes all of the M > 4 earthquakes to have occurred within the Salton Sea Geothermal Field in the last 15 years, ruptured the Main Central Fault (MCF) system that is localized in the heart of the geothermal anomaly. The background microseismicity induced by the geothermal operations is also concentrated in the high-temperature regions in the vicinity of operational wells. However, while this microseismicity occurs over a few kilometer scale region, much of it is clustered in earthquake swarms that last from hours to a few days and are localized near the MCF system.
    Description
    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 120 (2015): 2600–2615, doi:10.1002/2014JB011579.
    Collections
    • Geology and Geophysics (G&G)
    Suggested Citation
    Journal of Geophysical Research: Solid Earth 120 (2015): 2600–2615
     

    Related items

    Showing items related by title, author, creator and subject.

    • Thumbnail

      Thermal-mechanical behavior of oceanic transform faults : implications for the spatial distribution of seismicity 

      Roland, Emily C.; Behn, Mark D.; Hirth, Greg (American Geophysical Union, 2010-07-01)
      To investigate the spatial distribution of earthquakes along oceanic transform faults, we utilize a 3-D finite element model to calculate the mantle flow field and temperature structure associated with a ridge-transform-ridge ...
    • Thumbnail

      The influence of geothermal sources on deep ocean temperature, salinity, and flow fields 

      Speer, Kevin G. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1988-05)
      This thesis is a study of the effect of geothermal sources on the deep circulation, temperature and salinity fields. In Chapter 1 background material is given on the strength and distribution of geothermal heating. In ...
    • Thumbnail

      Seismic velocity constraints on the material properties that control earthquake behavior at the Quebrada-Discovery-Gofar transform faults, East Pacific Rise 

      Roland, Emily C.; Lizarralde, Daniel; McGuire, Jeffrey J.; Collins, John A. (American Geophysical Union, 2012-11-17)
      Mid-ocean ridge transform faults (RTFs) vary strongly along strike in their ability to generate large earthquakes. This general observation suggests that local variations in material properties along RTFs exert a primary ...
    All Items in WHOAS are protected by original copyright, with all rights reserved, unless otherwise indicated. WHOAS also supports the use of the Creative Commons licenses for original content.
    A service of the MBLWHOI Library | About WHOAS
    Contact Us | Send Feedback | Privacy Policy
    Core Trust Logo