Preliminary Report on the Feasibility of Using Synthetic Aperture Radar Interferometry to Image Localized Strain as a Discriminator of Geothermal Resources

PDF Version Also Available for Download.

Description

Most producing geothermal fields and known geothermal resources in the Basin and Range province are associated with Quaternary active fault systems, within which hydrothermal fluids are presumed to circulate from depth to relatively shallow production levels through high permeability fractures. Research at the Dixie Valley field by Barton et al. (1997) indicates that hydraulically conductive fractures within the Stillwater fault zone are those that have orientations such that the fractures are critically stressed for normal shear failure under the regional tectonic stress field. In general, therefore, we might expect geothermal resources to occur in areas of high inter-seismic strain accumulation, ... continued below

Physical Description

PDF-file: 30 pages; size: 2.5 Mbytes

Creation Information

Foxall, W June 15, 2005.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Author

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

Most producing geothermal fields and known geothermal resources in the Basin and Range province are associated with Quaternary active fault systems, within which hydrothermal fluids are presumed to circulate from depth to relatively shallow production levels through high permeability fractures. Research at the Dixie Valley field by Barton et al. (1997) indicates that hydraulically conductive fractures within the Stillwater fault zone are those that have orientations such that the fractures are critically stressed for normal shear failure under the regional tectonic stress field. In general, therefore, we might expect geothermal resources to occur in areas of high inter-seismic strain accumulation, and where faults are favorably oriented with respect to the regional strain tensor; in the case of Basin and Range normal faults, these would generally be faults striking normal to the direction of maximum extension. Expanding this hypothesis, Blewitt et al. (2003), based on preliminary, broad-scale analysis of regional strain and average fault strike in the northwestern Basin and Range, have proposed that geothermal resources occur in areas where fault-normal extension associated with shear strain is the greatest. Caskey and Wesnousky (2000) presented evidence that the Dixie Valley field occupies a 10 km-long gap between prehistoric Holocene ruptures of the fault segments on either side. Modeled maximum shear and Coulomb failure stress are high within the gap owing to the stress concentrations at the ends of the ruptures. These results suggest that a major contributing factor to the enhanced permeability at fault-hosted geothermal systems may be localized stress and strain concentrations within fault zone segments. This notion is generally consistent with the common occurrence of geothermal fields within fault offsets (pull-aparts) along strike-slip fault systems, where the local strain field has a large extensional component (e.g., Salton Sea and Coso). Blewitt et al. (2003) suggested that resources correlate with abrupt changes in fault orientation and with changes in the direction of extensional strain.

Physical Description

PDF-file: 30 pages; size: 2.5 Mbytes

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: UCRL-TR-213040
  • Grant Number: W-7405-ENG-48
  • DOI: 10.2172/877907 | External Link
  • Office of Scientific & Technical Information Report Number: 877907
  • Archival Resource Key: ark:/67531/metadc874191

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • June 15, 2005

Added to The UNT Digital Library

  • Sept. 21, 2016, 2:29 a.m.

Description Last Updated

  • Nov. 30, 2016, 6:09 p.m.

Usage Statistics

When was this report last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Foxall, W. Preliminary Report on the Feasibility of Using Synthetic Aperture Radar Interferometry to Image Localized Strain as a Discriminator of Geothermal Resources, report, June 15, 2005; Livermore, California. (digital.library.unt.edu/ark:/67531/metadc874191/: accessed September 23, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.