Preliminary result of earthquake hypocenter determination using hypoellipse around western Java region

Abstract

West Java region is located in high seismicity and active tectonic setting region influenced by subducting Indo-Australian plate beneath Eurasia plate. There are several on land active faults namely Cimandiri fault, Lembang fault, and Baribis fault in the region. MCGA earthquake data catalog from 2009 to 2014 shows the earthquakes were located not only around active faults but also relatively far away from the active faults in West Java region. In this study, we determined the earthquake location through re-picking of P-and S-wave arrival times recording by MCGA network. Earthquake location was determined by using Hypoellipse code that employs a single event determination method. We then relocated the events using hypocenter double-difference method. We also have been conducting focal mechanism analysis to estimate the type of fault slip. Our preliminary results show generally the epicenter location were distributed around the on land active fault which have the focus depth less than 30 km. For ongoing and future works, we have been determining focal mechanism of selected event related to on land active fault for this region..