New constraints on relative motion between the Pacific Plate and Baja California microplate (Mexico) from GPS measurements |
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| Authors: | C Plattner R Malservisi T H Dixon P LaFemina G F Sella J Fletcher F Suarez-Vidal |
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| Institution: | Sektion Geophysik der Ludwig-Maximilians Universität, Theresienstr.;41, 80333 München, Germany. E-mail: Rosenstiel School of Marine and Atmospheric Sciences, University of Miami,;4600 Rickenbacker Causeway, Miami, FL 33149 , USA National Geodetic Survey, NOAA,;1315 East-West Highway, Silver Spring, MD 20910, USA Centro de Investigacion Cientifica y Educacion Superior de Ensenada, Km.;107 Carretera Tijuana Ensenada, Ensenada BC 2732, Mexico |
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| Abstract: | We present a new surface velocity field for Baja California using GPS data to test the rigidity of this microplate, calculate its motion in a global reference frame, determine its relative motion with respect to the North American and the Pacific plates, and compare those results to our estimate for Pacific–North America motion. Determination of Pacific Plate motion is improved by the inclusion of four sites from the South Pacific Sea Level and Climate Monitoring Project. These analyses reveal that Baja California moves as a quasi-rigid block but at a slower rate in the same direction, as the Pacific Plate relative to North America. This is consistent with seismic activity along the western edge of Baja California (the Baja California shear zone), and may reflect resistance to motion of the eastern edge of the Pacific Plate caused by the 'big bend' of the San Andreas fault and the Transverse Ranges in southern California. |
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| Keywords: | geodesy global positioning system (GPS) plate tectonics tectonics |
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