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[SSS30-P06] The M 7.7 September 24, 2013 Pakistan earthquake: comparison of back-projection images and field data
Keywords:source process, back-projection, slip model, rupture speed
High frequency images suggest that the average rupture speed is 4.0 to 5.0 km/s. The rupture speed seems relatively slow (1.0 to 2.0 km/s) for the first 10-15s, and then increased to fast, possibly supershear (4.0 to 6.0 km/s). Relatively lower frequency images show a lower rupture speed of 3.0 to 3.5 km/s (Figure 1).
A comparison of rupture traces determined by the back-projection and a geodetic study provides a good test for resolution of the back-projection method. Given a correct epicenter location, results derived from seismograms recorded in Hi-net, show a very accurate location of the surface trace with an uncertainty of 10-20 km.
Figure 1 Timings and amplitudes for the stack with the maximum correlation at each time step (1 s) showing in the map (top) and as a function of time derived from data recorded in Europe, China, and Japan (from left to right) filtered in several high frequency bands (bottom). Here the distance is measured in a straight line from the relocated epicenter.