A Report Of The December 6, 2016 Mw 6.5 Pidie Jaya, Aceh Earthquake
Abstract
The December 6, 2016 Mw 6.5 earthquake in Pidie Jaya, Aceh was one of the devastating inland earthquakes in Sumatra that took away more than 100 people's life. Here we present our seismological analysis of the earthquake sequence. The earthquake focal mechanism inversions using regional BMKG broadband data and teleseismic waveform data all indicate a strike-slip focal mechanism with a centroid depth of 15 km. Preliminary finite fault inversion using teleseismic body waves prefers the fault plane with strike of 45 degree and dip of 50 degree, in agreement with the surface geology and USGS aftershock distributions. Nine broadband seismic stations were installed in the source region along the coast one week after the earthquake and have collected the data for one month. The data have been used to locate aftershocks with grid search and double-difference algorithm, which results in the lineup of the seismicity in NE-SW direction, in agreement with the fault inversion and geology results. Using the M4.0 calibration earthquake that was recorded by the temporally network, we relocated the mainshock epicenter, which is also consistent with fault geometry defined by the well located aftershocks. In addition, a portion of the seismicity shows a lineation in E-W direction, indicating a secondary fault that has not been identified before. Aftershock focal mechanisms determined by the first motion reveal similar solutions as the mainshock. The observed macro intensity data shows most of the damaged buildings are distributed along the coast, approximately perpendicular to the preferred fault strike instead of parallel with it. It appears that the distribution of damage is strongly related to the site conditions, since these strong shaking/damage regions are mainly located on the costal sedimentary soils.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.S53B0688M
- Keywords:
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- 7209 Earthquake dynamics;
- SEISMOLOGY;
- 7215 Earthquake source observations;
- SEISMOLOGY;
- 7221 Paleoseismology;
- SEISMOLOGY;
- 7230 Seismicity and tectonics;
- SEISMOLOGY