F. Khairina1 , T.A. Prakoso1 , S. Wei2
1Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG), National Seismological Center, Jakarta, Indonesia
2Earth Observatory of Singapore, Nanyang Technical University, Singapore
The destructive earthquake that occurred on December 7th 2016 in the western part of Aceh, caused damage to buildings and loss of life. We estimated the earthquake source parameters using regional broadband waveform data with the Cut and Paste (CAP) inversion method to better understand this earthquake and the seismic hazard in the region. Our results indicate that the best solution of this event is strike 240 deg., dip 53 deg. and rake 9 deg. for the first nodal plane, and strike 144.6 deg., dip 82.8 deg. and rake 142.7 deg. for the second nodal plane, with 16 km for the centroid depth. Our focal mechanism solution is consistent with those of other agencies, i.e. USGS and Global centroid moment tensor (CMT), and also in agreement with the aftershock distribution that has been relocated with the teletomoDD method. The aftershock distribution shows that the earthquake fault corresponds to the second nodal plane. Moreover, we do coloumb stress analysis, our result show that more than 80% of the aftershocks are distributed in the positive Coulomb stress increased zones. Our focal mechanism solutions and spatial distribution of the relocated aftershocks suggests that the earthquake is classified as a typical unidentified reverse-fault earthquake.