Characterization of Fracture Patterns in the Geysers Geothermal Reservoir by Shear-wave Splitting Metadata

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  • Main Title Characterization of Fracture Patterns in the Geysers Geothermal Reservoir by Shear-wave Splitting


  • Author: Erten, D.
    Creator Type: Personal
  • Author: Rial, J. A.
    Creator Type: Personal


  • Sponsor: United States. Department of Energy. Office of Energy Efficiency and Renewable Energy.
    Contributor Type: Organization
    Contributor Info: USDOE Office of Energy Efficiency and Renewable Energy (EE) (United States)


  • Name: USDOE Idaho Operations Office, Idaho Falls, ID
    Place of Publication: United States
  • Name: University of North Carolina, Chapel Hill, NC (United States)
    Place of Publication: United States


  • Creation: 1999-09-15


  • English


  • Content Description: The authors have analyzed the splitting of shear waves from microearthquakes recorded by a 16-station three-component seismic network at the Northwest Geysers geothermal field, Geysers, California, to determine the preferred orientation of subsurface fractures and cracks. Average polarization crack directions with standard deviation were computed for each station. Also, graphical fracture characterizations in the form of equal-area projections and rose diagrams were created to depict the results. The main crack orientations within the steam field are predominantly in the N10{degree}E to N50{degree}E direction, consistent with expected fracture directions in a pull-apart basin created by sub-parallel right-lateral strike-slip faults related to the San Andreas fault system. Time delays range from 15--60 ms, similar to the time delays from previous studies at geothermal reservoirs. They have detected a significant increase in time delays between 1988 and 1994, which they attribute to widening of the cracks or filling of the cracks with fluid. Increase in production activities during this time also could have influenced this widening.
  • Physical Description: 14 p.


  • Keyword: Geysers Geothermal Field
  • Keyword: Northwest Geysers
  • Keyword: Microearthquakes
  • Keyword: Seismic Surveys
  • Keyword: Natural Steam
  • Keyword: Polarization
  • Keyword: Seismic S Waves Geothermal Legacy
  • Keyword: Geothermal Legacy
  • Keyword: Geothermal Reservoirs
  • Keyword: Geologic Fractures
  • Keyword: Time Delays
  • STI Subject Categories: 15 Geothermal Energy
  • Keyword: Shear Waves
  • Keyword: Crack Orientation
  • Keyword: Subsurface Fractures


  • Other Information: PBD: 15 Sep 1999


  • Name: Office of Scientific & Technical Information Technical Reports
    Code: OSTI


  • Name: UNT Libraries Government Documents Department
    Code: UNTGD

Resource Type

  • Report


  • Text


  • Report No.: DOE/ID/13468
  • Grant Number: FG07-96ID13468
  • DOI: 10.2172/758724
  • Office of Scientific & Technical Information Report Number: 758724
  • Archival Resource Key: ark:/67531/metadc711996


  • Display Note: OSTI as DE00758724
  • Display Note: Medium: P; Size: 14 pages