The non-volvanic tremor observer in Oaxaca segment and Taiwan
Speaker: Xin-Song Xie
Abstract
Non-volcanic tremor (NVT) is a subtle seismic signal with long durations and no clear body wave arrivals observed away from volcanic regions. Tremor often accompanies slow-slip events, and together they are termed episodic tremor and slip. Tremor has been found at many places along the circum-pacific subduction zones and the transform plate boundary in California. In recent studies , we know that tremor appears to be highly stress sensitive, and can be triggered instantaneously by the passing surface waves . For the Oaxaca segment, eighteen prominent NVT episodes were identified during the 15 months analyzed. NVT burst epicenters primarily occur between the 40–50 km contours for depth of the plate interface, and the NVT hypocenters correlate well with a high conductivity zone that is interpreted to be due to slab fluids . In Taiwan, Peng and Chao show clear evidence of the NVT which exist beneath the Central Range causing by the Mw 7.8 Kunlun earthquake, and it's the first time that NVT detected in Taiwan . 2 years later , Tang et al also detected the NVT in the similar place by examining the Mw 8.6 Nias earthquake . The epicenters of the triggered tremors are consistent with the high Vp/Vs ratio zone causing by the dehydration.
Reference
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