Analysis of Aftershocks Distribution of the June 16, 2010 Yapen Earthquake Based on Stress Changes on the Fault Plane.

Abstract

On June 16, 2010, an earthquake (Mw 7.0) occurred on the north of the Papua island close to Yapen island. The area of earthquake source has been well identified due to the activity of faults which are formed by collision of four minor plates. The source mechanism of the June 16, 2010 Yapen earthquake was strike-slip fault type with two nodal planes. Determination of the actual fault plane of nodal planes is important for a detailed study of seismotectonics and earthquake risk assessment.In this study, we relocated the mainshock and aftershocks by using the Double-Difference algorithm, and analyzed the stress changes by using the Coulomb stress method on the study area. Furthermore, the determination of the actual fault plane was obtained by using the H-C method (Hypocenter-Centroid method). We used earthquake data from the Meteorology Climatology and Geophysics Agency (BMKG) and the Global Harvard Centroid Moment Tensor (CMT Global Harvard). Study results show that the relocated aftershock distribution lies close to the increase in stress coseismic area. The increase in stress coseismic area occurred at the nodal plane II as the actual fault plane. This results proved that the aftershock distribution was correlated to the actual fault plane.