Crustal Structure from Calibrated Earthquake Locations (Postprint)
Technical paper 1 Sep 2010-7 Mar 2012
COLORADO UNIV AT BOULDER
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An extensive and high-quality data set of earthquake locations, many of them calibrated to GT590 levels of accuracy, has been compiled for the region that expresses the continental collision between the Arabian and Eurasian plates, with the primary goal of using a calibrated data set to obtain an unbiased baseline model of the crustal and upper mantle velocity structure through tomographic imaging. A specialized multiple event relocation algorithm based on the Hypocentroidal Decomposition HDC method has been used to calibrate clusters of earthquakes, using several kinds of available calibration data, including near-source seismic observations, results of InSAR analyses on source location and faulting mechanism, results of waveform modeling for depth control, and mapped faulting. The data set is derived from 35 calibrated clusters containing 1834 events, ranging in magnitude from near 2.0 to greater than 7.0. Of these calibrated events, 1699 qualify for GT590 and 1134 qualify at GT390. All clusters except one containing 8 events have been calibrated for origin time. Therefore the observed arrival times from nearly all events in the data set can be taken as estimates of the true travel time of the corresponding seismic phase through the crust and upper mantle of the region.