Zhongwen Zhan

Rupture complexity of deep earthquakes: the large, the hot, and the fast

Zhongwen Zhan

Institute of Geophysics and Planetary Physics
Scripps Institution of Oceanography, UC San Diego

Wednesday, April 23rd, 2014
CSL 422 – 12:00am

The physical mechanism of deep earthquakes (depth>300 km) remains enigmatic, partly because their rupture processes are difficult to resolve due to absence of near-field observations. In this talk, I will present a new sub-event method to perform full teleseismic and regional P-waveform inversion for deep earthquake rupture models. I apply this new method to the 1994 Mw 8.2 Bolivia earthquake, the 2013 Mw 8.3 Sea of Okhotsk earthquake and one of its large aftershocks (Mw 6.7). I find that their rupture properties are very different, namely, the Mw 8.3 Okhotsk event is large, the Mw 8.2 Bolivia is hot, and the Mw 6.7 Okhotsk is fast.  We explain the observed differences among the three earthquakes as resulting from two fundamentally different faulting mechanisms in slabs with different thermal states.

 

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