Southeast Asia Seismology

To better understand the earthquakes and associated tectonic setting and ground shaking, we propose to study earthquakes in Southeast Asia, the most seismically active region on the earth, with a series of broadband waveform modeling tools. The proposed works include systematic determination of earthquake focal mechanisms and depth, simulation of broadband ground shaking for scenario earthquakes in the Mentawai seismic gap, and determination of fault morphology using high-frequency waveform modelling of aftershocks from great earthquakes.

In 2017 we successfully applied these techniques to Nepal, Mentawai, and Illapel subduction zones as well as Kumamoto region in Japan, which have provided some new insights into tectonics and earthquake mechanisms.

We have developed broadband waveform modelling techniques and tools to improve the resolution of fault geometry imaging. In the last year, we have successfully evidenced the double-ramp geometry of MTH, clarified the 2005/2009 Mentawai "backthrust" events should have occurred on backstop faults, revealed the anti-dipping fault geometry of the Mw6.2 Kumamoto foreshock and the unilateral rupture of the Mw7.1 mainshock, as well as identified an unmapped left-lateral strike-slip fault in Aceh that hosted the deadly 2016 December 6 Mw6.5 Pidie Jaya earthquake with temporal seismic stations. Combining geodetic and seismic data modelling, we have also shown that the 2017 September 3 North Korea underground nuclear test was followed by a collapsing event 8 minutes 32 seconds after the main explosion.

Funding Sources: 

  • Earth Observatory of Singapore

Project Years: 

2016
2017
2018

EOS Team: 

Principal Investigator
Co-Investigator
Co-Investigator
Co-Investigator
Co-Investigator
Co-Investigator
Co-Investigator
Co-Investigator

Collaborators: 

Wenbo Wu, Department of Geoscience, Princeton

Muksin Umar, Syiah Kuala University