A geodetic strain rate model for the Pacific-North American plate boundary, western United States [FULL-SIZE PLATE]; by Corne Kreemer, William C. Hammond, Geoffrey Blewitt, Austin A. Holland, and Richard A. Bennett; 2012

This map presents a model of crustal strain rates derived from Global Positioning System (GPS) measurements of horizontal station velocities. The model indicates the spatial distribution of deformation rates within the Pacific–North America plate boundary from the San Andreas fault system in the west to the Basin and Range province in the east. As these strain rates are derived from data spanning the last two decades, the model reflects a best estimate of present-day deformation. However, because rapid transient effects associated with earthquakes (i.e., postseismic deformation resulting in curvature of the GPS time-series) have been removed from the GPS data, these strain rates can be considered representative of the long-term, steady-state, deformation associated with the accumulation of strain along faults. This model is useful for both seismic-hazard and geodynamic studies to understand the activity rates of (known and unknown) faults and the plate tectonic boundary and buoyancy forces that cause the deformation, respectively. In more slowly deforming areas we expect fewer, smaller earthquakes and infrequent large earthquakes will have a much longer recurrence time compared to those in rapidly deforming areas.

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Map 178, one 48x46-inch color plate, scale 1:1,500,000, rolled only, $46.00