• 首页关于本刊投稿须知期刊订阅编委会期刊合作查询检索English

查看全文   查看HTML全文 下载PDF阅读器  

  李彦宝,王虎,刘华国,陈立春.甘孜-玉树断裂当江段地表破裂遗迹与1738年玉树西北地震的讨论[J].震灾防御技术,2016,11(2):207-217, DOI:10.11899/zzfy20160204.

甘孜-玉树断裂当江段地表破裂遗迹与1738年玉树西北地震的讨论
摘要:    对历史记载的公元1738年玉树西北地震的震级及其发震构造目前仍存有争议。卫星影像解译和野外调查发现沿甘孜-玉树断裂当江段分布一条长约75km的左旋走滑地震地表破裂带,其最大同震水平位移约2.1m。综合分析该地表破裂带特征、探槽揭露信息、测年结果以及历史文献记载等资料,认为当江段应为1738年玉树西北地震的发震断层,基于震例类比和经验公式估算该次地震的震级为71/2级。沿甘孜-玉树断裂的历史地震破裂分布显示,玉树段在隆宝镇以西存在近50km长的破裂空段;当江段距1738年地震的离逝时间也可能已经接近其地震复发周期,上述两个段落未来均存在大震危险。
作者单位
李彦宝 中国地震局地质研究所北京 100029 
王虎 中国地震灾害防御中心北京 100029 
刘华国 中国地震局地质研究所北京 100029 
陈立春 中国地震局地质研究所北京 100029 
关  键  词:甘孜-玉树断裂  当江段  地表破裂遗迹  1738年玉树西北地震  发震构造
DOI:10.11899/zzfy20160204
基金项目:地震行业科研专项项目(201408014)“芦山7.0级地震孕育发生机理及其影响研究”和中国地震局玉树地震科学考察项目共同资助
收稿日期:2015-11-05
作者简介:李彦宝,男,生于1981年。2013年获博士学位,现从事博士后研究。主要研究方向为活动构造、古地震和GPS地壳形变与构造运动等。E-mail: liyanbao163@163.com
通讯作者:陈立春,男,生于1970年。2011年获博士学位,研究员。主要从事活动构造、古地震与地震中长期预测方面的研究。电话:010-62009086,E-mail: dzsclc@ies.ac.cn
The Surface Rupture Remains along the Dangjiang Segment of Garzê-Yushu Fault and the 1738 AD Earthquake
Abstract:      According to historical records, a destructive earthquake occurred in 1738 AD was recognized to be located at the northwest of Yushu, Qinghai Province. However, there is still some disputes about the magnitude and seismogenic structure of the earthquake. In this paper, based on the image interpretation (from ETM, Google Earth and SRTM data) and field investigation, a surface rupture zone were found along the Dangjiang segment of the Garzê-Yushu fault, which is a major active sinistral strike-slip fault in the Tibetan Plateau. The surface rupture zone, with length of ~75 km and maximum co-seismic horizontal displacement of ~2.1 m, were mainly characterized by sinistral strike-slip offset. The data of the feature of the surface rupture zone, trenching, 14C dating and the historical records about the 1738 AD earthquake indicate that the surface rupture zone along the Dangjiang fault segment is in accordance with the 1738 AD earthquake in time and space. Furthermore, by comparing with the 2010 Yushu MS7.1 earthquake and the 1973 Luhuo M7.6 earthquake and calculating of empirical formulas, we proposed that the surface rupture along the Dangjiang fault segment is seismogenic structure of the 1738 AD earthquake and the magnitude of the historical event should be about M71/2. The distribution of surface ruptures related to historical earthquakes along the Garzê-Yushu fault implies that there is a seismic gap with length of about 50km to the west of Longbao town of the Yushu segment. Otherwise, the elapsed time since the 1738 AD earthquake of the Dangjiang segment is likely close to its recurrence interval. Future large earthquakes are likely to occur along the two fault segments.
Keywords:  Garzê-Yushu fault  Dangjiang segment  Surface rupture remains  1738AD earthquake  Seismogenic structure
关闭