Determination of the earthquake source parameters using W-Phase inversion method and its uses for tsunami modelling

Abstract

This study performed W-Phase inversion for eight events with large magnitude (M>7) that occured in Indonesia for the period of 2006-2016 by using global data obtained from IRIS DMC (Incorporated Research Institutions for Seismology Data Management Center). The results of W-Phase inversion; both moment magnitude and focal mechanism were generally similar with the Global CMT (Centroid Moment Tensor) solutions. The result shows that maximum deviation of moment magnitude was 0,09 and the average of magnitudo deviation was 0.03625. Comparison of moment magnitude (Mw) indicates that seismic moments from Global CMT and W-Phase inversion are larger than that from body waves, especially for the 2010 Mentawai earthquake. Tsunami simulation was performed using two different source parameters and sea floor deformation, from Global CMT and W-Phase inversion to get arrival times and heights on the coasts to be validated by observation tide gauge data from IOC (Intergovernmental Oceanographic Commission). The simulation shows that these two models; Global CMT and W-Phase inversion yields similar tsunami arrival times and heights on the coasts, but they have a bit difference with the observation data for some tide gauge station.