Southeast Asia and Global Seismology
To better understand the earthquakes and associated tectonic setting and ground shaking, we study earthquakes in Southeast Asia, the most seismically active region on the earth. We also study significant earthquakes at a global scale, as they usually are recorded by dense observations, providing a unique opportunity to understand earthquake physics. We systematically determine earthquake focal mechanisms and depth, simulate broadband ground shaking for scenarios and real earthquakes, and determine fault morphology using high-frequency waveform modelling of seismicity. These researches involve with application and development of modern waveform inversion and modelling techniques, joint inversion of multiple datasets (e.g. geodetic and seismic), and making geologic and tectonic interpretations of the results.
We have studied earthquakes in Nepal, New Zealand, Malaysia, China, the US, and South Chile as well as Japan. Taking the 2015 Mw7.8 earthquake sequence in Nepal as an example, we published a series of papers that provide the most comprehensive seismological analysis of the sequence. We provided detailed coseismic rupture models of the mainshock and its Mw7.3 aftershock (Wei et al., 2018; Avouac et al., 2015), we obtained high-resolution aftershock focal mechanisms and relocations that delineate a double-ramp fault geometry (Wang et al., 2017), and we conducted broadband ground-motion simulations for the mainshock and its Mw7.3 aftershock, the modelling of strong-motion data in Kathmandu revealed strong stress drop contrast between the mainshock and the aftershock (Chen and Wei, 2019).
For studies in Bangladesh, my group has been working closely with Asst. Prof Hubbard’s group to merge their seismic observations in Bangladesh with the Myanmar seismic network, which produces a more comprehensive data coverage for both Myanmar and Bangladesh. We also studied source property and the associated neotectonics of the 2015 Mw 6.0 Mt. Kinabalu earthquake, which ruptured the Crocker fault system in East Malaysia (Wang et al., 2017). The rock falls produced by the shaking of the earthquake claimed the lives of seven Singaporean students and teachers who were hiking at mount Kinabalu during the earthquake. We revealed the anti-dipping fault geometry of the Mw6.2 Kumamoto foreshock and the unilateral rupture of the Mw7.1 mainshock (Shi et al., 2018). 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 (Wang et al., 2018).
- Earth Observatory of Singapore
Wang Xin, Institute of Geology and Geophysics, Chinese Academy of Sciences
Muzli, Meteorological, Climatological and Geophysical Agency (BMKG)
Wang Teng, Peking University
Wenbo Wu, Department of Geoscience, Princeton
Muksin Umar, Syiah Kuala University
Paul Tapponnier, National Institute of Natural Hazards, China
- Active backstop faults in the Mentawai region of Sumatra, Indonesia, revealed by teleseismic broadband waveform modeling. Earth and Planetary Science Letters. 483, 29-38. (2018).
- The 2015 Gorkha (Nepal) earthquake sequence: I. Source modeling and deterministic 3D ground shaking. Tectonophysics. 722, 447-461. (2018).
- The rise, collapse, and compaction of Mt. Mantap from the 3 September 2017 North Korean nuclear test. Science. (2018).
- Lithospheric radial anisotropy beneath the Gulf of Mexico. Earth and Planetary Science Letters. 466, 43-52. (2017).
- Double-ramp on the Main Himalayan Thrust revealed by broadband waveform modeling of the 2015 Gorkha earthquake sequence. Earth and Planetary Science Letters. 473, 83-93. (2017).