报告地点：Zoom(ID:724-620-904)
报告时间：2020-04-24 从 15:00 到 16:30
报告人：韦生吉
报告人简介：
I have been working as an assistant professor at the Asian Environment School and PI at the Earth Observatory of Singapore, Nanyang Technological University, since 2014. I obtained bachelor and PhD degrees in geophysics in USTC in 2004 and 2009, respectively, this was followed by a postdoc career at the Seismolab at Caltech. My research interests are mainly focused on earthquake source studies both in real time and later in-depth studies. I am also interested in structures properties to better understand earthquake sources and tectonic and geodynamic processes. My research experiences cover both natural and man-made earthquakes. My approach for resolving the kinematic nature of earthquakes involves the combination of geodesy, geology and seismology to better constrain the spatial-temporal evolution of seismic rupture properties. Besides reconciling various datasets, I also developed techniques that allow waveform inversion/modelling to be extended to the higher frequency (>1Hz) range of relevance for damage assessment.
报告题目：Thermal squeezing of the seismogenic zone controlled multiple ruptures of the volcano-rooted Flores Thrust
报告内容简介:
The 2018 Lombok earthquake swarm provides a unique opportunity to investigate the fundamental physics that governs the complex rupture on a fluid enriched fault that has strong thermal gradient. The sequence is distributed beneath the northern coast of the Lombok island on the Flores Fault, composing of two Mw6.4 and two Mw6.9 earthquakes and numerous aftershocks. Interestingly, the first Mw6.9 event shows much more asperities, hence more patchy rupture, compared with the second Mw6.9 event. The seismicity captured by 13 seismometers deployed on the island just before the first Mw6.9 event mostly concentrated within a narrow depth range (~5km). The squeezed seismicity and coseismic rupture of the largest events is highly consistent with a volcanic-rooted thermal model, characterized with the elevated depth of the Brittle-Ductile-Transition (BDT) zone. Repeating/similar earthquakes were identified and are mostly located in the rupture area of the first Mw6.9 event, with a large portion overlapping with coseismic slip. This indicates a highly heterogeneous friction and incomplete coseismic rupture on the fault that is probably caused by the stronger thermal gradient compared with the second Mw6.9 event.