UPDATE OF THE PACIFIC NORTHWEST GPS-DERIVED VELOCITY … · 2011-05-16 · UPDATE OF THE PACIFIC...
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UPDATE OF THE PACIFIC NORTHWEST GPS-DERIVED VELOCITY FIELD Robert McCaffrey ([email protected]) Department of Geology, Portland State University, Portland OR 92707 Robert W. King ([email protected]) Dept. of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 Suzette J. Payne ([email protected]), Idaho National Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415 We present an update of the Pacific Northwest GPS-derived surface velocity field presented earlier by McCaffrey et al. (Geophys. Jour. Int., 2007) and Payne et al. (Geology, 2008). The velocity field combines new SOPAC daily solutions for 1994-2010 for the BARGN, EBRY, PANGA, PBO, and WCDA networks (http://sopac.ucsd.edu/processing/gamit ) with our solutions using data from field surveys conducted by us and several other institutions from 1991-2010. The new field reveals that the large-scale clockwise rotation seen in western Washington and Oregon also extends southward into southern Idaho and the Snake River Plain as well as into the northern Basin and Range of Nevada. The axes of rotation generally fall near the Oregon-Washington-Idaho border. Significant permanent strain rates are localized at the Wasatch fault, the Walker Lane, and parts of the Basin and Range. Otherwise large areas of the Pacific NW rotate relative to North America as nearly rigid blocks. The Cascadia subduction zone imparts an elastic strain rate of up to 10 -7 /yr on the western edge of North America. We present a revised locking model for Cascadia based on these velocities and coastal uplift rates from leveling by Burgette et al. (J. Geophys. Res., 2009). Detailed interpretations of the Snake River Plain region based on this velocity field are presented by Payne et al. (this meeting).
Transcript of UPDATE OF THE PACIFIC NORTHWEST GPS-DERIVED VELOCITY … · 2011-05-16 · UPDATE OF THE PACIFIC...
UPDATE OF THE PACIFIC NORTHWEST GPS-DERIVED VELOCITY FIELD Robert McCaffrey ([email protected]) Department of Geology, Portland State
University, Portland OR 92707 Robert W. King ([email protected]) Dept. of Earth, Atmospheric & Planetary
Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 Suzette J. Payne ([email protected]), Idaho National Laboratory, P.O. Box 1625,
Idaho Falls, Idaho 83415 We present an update of the Pacific Northwest GPS-derived surface velocity field
presented earlier by McCaffrey et al. (Geophys. Jour. Int., 2007) and Payne et al. (Geology, 2008). The velocity field combines new SOPAC daily solutions for 1994-2010 for the BARGN, EBRY, PANGA, PBO, and WCDA networks (http://sopac.ucsd.edu/processing/gamit) with our solutions using data from field surveys conducted by us and several other institutions from 1991-2010. The new field reveals that the large-scale clockwise rotation seen in western Washington and Oregon also extends southward into southern Idaho and the Snake River Plain as well as into the northern Basin and Range of Nevada. The axes of rotation generally fall near the Oregon-Washington-Idaho border. Significant permanent strain rates are localized at the Wasatch fault, the Walker Lane, and parts of the Basin and Range. Otherwise large areas of the Pacific NW rotate relative to North America as nearly rigid blocks. The Cascadia subduction zone imparts an elastic strain rate of up to 10-7 /yr on the western edge of North America. We present a revised locking model for Cascadia based on these velocities and coastal uplift rates from leveling by Burgette et al. (J. Geophys. Res., 2009). Detailed interpretations of the Snake River Plain region based on this velocity field are presented by Payne et al. (this meeting).
