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The Spokane Fault. Me Craig Weaver Paul Bodin (PNSN) Brian Sherrod. 1. Conclusions:. There is an active shallow reverse fault beneath the city of Spokane, Washington. Slip on the fault occurred during the 2001 earthquake sequence. Slip was shallow (from ~0.3 to 2 km depth).
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The Spokane Fault Me Craig Weaver Paul Bodin (PNSN) Brian Sherrod 1
Conclusions: There is an active shallow reverse fault beneath the city of Spokane, Washington. Slip on the fault occurred during the 2001 earthquake sequence. Slip was shallow (from ~0.3 to 2 km depth). The direction of slip (NNW) is consistent with regional contraction determined from geology, which isdifferent from McCaffrey’s [2013] GPS derived contraction direction of North-NNE. 2
The PNSN seismic network was optimal during the month of July, 2001. The red triangles show the location of the temporary July seismic array and the red circles show the location of the earthquakes that occurred during July 2001. Time history of seismicity is shown with the time spanned by the six interferograms in the next slide. 3
We invert for the Vertical and East components of deformation using the interferograms (2-5) shown in the previous slide. 5
Best-Fit model a shallow thrust fault dipping to the NW. Model fault line (black dashed line) passes through Spokane Falls. Cross-section X-X’ Slipping fault (solid lines) showing dip of 19 to 43 degrees. 6
Parsed data and comparison between data and calculated from best-fit 7
Model fault line in downtown Spokane, GoogleEarth Looking NE 11