Rupture process and characteristics of Longmen shan thrust belt, China

Speaker:

Shiou-chuan Liu

Date: 2013/12/19

Abstract

On 12 May 2008, the Wenchuan earthquake (Mw 7.9) produced complicated thrust-type co-seismic surface rupture zones, and formed the three major, Beichuan –Yingxiu fault, Pengzhou-Guanxian fault and Xiayudong rupture, respectively. Beichuan –Yingxiu fault the local name is center fault which was Wenchuan earthquake seismogenic faults, Pengzhou -Guanxian fault also called the front fault, it is eastern margin in Longmen shan area, Xiaoyudong rupture which linked the former two. Before the detailed field investigation, some researchers supported that Xiaoyudong fault is a tear fault, but observe the fault plane with the co-seismic fault striations, we can further to understand how it slip along the fault plane. After that, the results of an investigation show the Xiaoyudong fault has thrusting and sinistral strike-slip just like a ramp. Based on the geologic studies and the surface rupture investigation, scientists constructed a more realistic double-listric finite-fault model, and reconstructed the source rupture process by combined inverting the teleseismic waveforms and local coseismic displacement. Results show that the Wenchuan earthquake is characterized mainly by thrust motion with right-lateral strike slip.

Reference