The Great Basin area in the western United States is part of the Pacific-North America plate boundary zone. This explains its spectacular and changing landscape and its occasional earthquakes. The morphology, geology and geodetic data indicate that most of the Great Basin is under extension. However, because the Pacific plate is not moving away from North America (they are sliding past each other) the extension in the Great Basin is still difficult to explain. To test competing mechanisms, it is important to model the regional strain rate field. We do this mainly by using GPS velocity measurements.
The figure shows a strain rate map of the Great Basin (see Kreemer, C. W.C. Hammond, G. Blewitt, A.A. Holland and R.A. Bennett, (2012) A geodetic strain rate model for the Pacific-North American plate boundary, western United States. Nevada Bureau of Mines and Geology Map 178, scale 1:1,500,000.
