STRONG GROUND MOTION SIMULATION OF THEJANUARY 13, 2001 EL SALVADOR EARTHQUAKEUSING EMPIRICAL GREEN'S FUNCTION METHOD

摘要

In January and February 2001, a very intense seismic activity occurred in El Salvador, it caused manydamages in the country. The biggest two earthquakes with magnitude M_w= 7.7 and M_6.5 occurredexactly one month separation, the first one occurred on January 13 and the second one on February 13. Using the empirical Green's function method we simulated the January 13, 2001 earthquakeusing strong ground motion data (accelerograms) and an aftershock with magnitude M_w= 5.7. We usedsource spectral fitting method in order to find an estimation of parameters to be used in EGF method. Two fault plane models determined by previous studies were considered for the simulation inthis study. One has strike/ dip/ rake angles 306.°/ 48.°/ -107.° and another 297.°/ 58.°/ -93.°,respectively. For the former we tested two possibilities with the same asperity area (30 km x 30 km)but different number of subfaults. We performed the ground motion simulation for three stations with large PGA and PGVvalues and a clear directivity pulse. From the result we determined that the former fault modelprovided us with the best results obtained in this study. This fault model is composed by a grid of 36subfaults with individual area of 5 km x 5 km.