Hypocenters Relocation Using Double-Difference Method around Molucca Collision Zone

Eastern Indonesia is situated in a very complicated tectonic settings due to the converging of three major plates. Those plates do not have a clear boundary between each other. The boundary zone is covered by many microplates which converging or subducting to each other or create a large dimension of transform fault. Consequently, the region has a relatively higher seismic activity compared to others region in Indonesia, or even we can say, in the world. In this study, we attempt to achieve better hypocenter locations with double-difference method using local earthquake events compiled by MCGA of Indonesia. We selected 3,666 events from 42 stations for time periods of January 2010 to December 2015 which occurred in area around Molucca Collision Zone. Our results show better hypocenter location according to the RMS of time residual shifting. The most significant changes are in the shallow events where fix-depth effect had been removed. Overall, the relocated hypocenter locations show a better distribution to represent the tectonic setting.