Surface Rupture Features of the 2010 Yushu Earthquake and Its Tectonic Implication
详细信息
- 责任者：Sun Xinzhe (National Center for Active Fault Studies ; Institute of Geology ; China Earthquake Administration ; Beijing 100029 ; China) ; Xu Xiwei
- 刊名：Chinese Journal of Geophysics
- 出版年：2012
- 卷期：55(1)
- 关键词：玉树地震2010 ; Yushu earthquake 2010 ; 构造样式 ; tectonic style ; 青藏高原 ; Qinghai-Tibetan Plateau
- 页码：p.155-170
- 图表：10 illus., 1 table, 33 refs.
- 分类号：0500
- issnNo：ISSN0001-5733
- isbnNo：CN11-2074/P
摘要
Field investigations show that the Yushu,Qinghai Province,MS7.1 earthquake occurred on the Yushu segment of the Ganzê-Yushu fault in the Qinghai-Tibetan Plateau.Its surface rupture zone is distributed along the Yushu segment between Longbao Town and Jiegu Town and consists of shear cracks,transtensional cracks,transpressional cracks,tension cracks,mole tracks in right-stepovers or small pull-aparts in left-stepovers between en echelon cracks with left-lateral component.Those ruptures are en echelon to form an ～300°-striking earthquake surface rupture zone with a total length of about 65 km.The maximum co-seismic left-lateral displacement is 2.4 m.The width of the surface rupture zone is in general less than 30 m,showing a localized rupturing feature.The Yushu earthquake surface rupture zone can be divided into two relatively independent sections in left-step: the Jielong section ～15 km long with a maximum left-lateral slip of 0.66 m and Jiegu section ～ 31 km with a maximum left-lateral slip of 2.4 m,and between them is a 17 km-long-section where no surface ruptures occurred,which correspond to two subevents with MW6.4 and MW6.9,respectively.This kind of the surface rupture pattern shows that the Ganzê-Yushu fault,a seismogenic fault of the Yushu earthquake,is dominated by a pure left-lateral faulting and the eastward escape of the Qinghai-Tibetan Plateau exists.