Deformation of Mexico from continuous GPS from 1993 to 2008

作者：Marquez Azua B^*; DeMets C

来源：Geochemistry Geophysics Geosystems, 2009, 10(2): Q02003.

DOI：10.1029/2008GC002278

• tectonics

We combine the velocities of 13 continuous Global Positioning System stations from Mexico and 448 North American plate stations to better understand deformation and earthquake cycle effects in Mexico. Velocities estimated at the Mexican sites from high-quality GPS data collected since 2003 show no evidence for a previously reported eastward bias at sites in and near the Yucatan peninsula. The new velocities are compared to the predictions of two models, one in which all motion in Mexico is attributed to North American plate motion and the second of which attributes site motions to a combination of plate motion and the elastic effects of frictional coupling along the Mexican subduction zone and faults in the Gulf of California. The second model fits the velocities within their estimated uncertainties. Mainland Mexico thus moves with the North American plate to within 1 mm per year and undergoes elastic interseismic deformation far into its interior. Two stations inland from the Guerrero and Oaxaca segments of the Mexican subduction zone have alternated between several-year-long periods of landward motion and several-month-long periods of trenchward motion frequently since 1993, consistent with previously described, repeating transient slip events along the subduction interface. The motions of two stations inland from the Rivera plate subduction zone are dominated by the coseismic and postseismic effects of the M = 8.0, 9 October 1995 Colima-Jalisco earthquake and M = 7.5, 22 January 2003 Tecoman earthquake offshore from western Mexico.

• 出版日期2009-2-6