段虎荣^1,,
周仕勇²,
李闰¹,
陈胜雷¹,
闫全超¹
1. 西安科技大学测绘科学与技术学院, 西安 710054
2. 北京大学地球与空间科学学院, 北京 100871

基金项目: 国家自然科学基金（41304013），地理信息工程国家重点实验室开放基金（SKLGIE2017-M-3-3）资助


详细信息

作者简介: 段虎荣, 男, 1979年生, 副教授, 主要从事大地测量反演研究.E-mail:duanhurong@126.com

中图分类号: P315

收稿日期:2019-01-26
修回日期:2019-11-11
上线日期:2020-01-05

Relationship between the slip distribution of the Lushan earthquake fault and the Wenchuan earthquake fault

DUAN HuRong^1,,
ZHOU ShiYong²,
LI Run¹,
CHEN ShengLei¹,
YAN QuanChao¹
1. College of Geomatics, Xi'an University of Science and Technology, Xi'an 710054, China
2. School of Earth and Space Sciences, Peking University, Beijing 100871, China


MSC: P315

--> Received Date: 26 January 2019
Revised Date: 11 November 2019
Available Online: 05 January 2020


摘要
摘要:本文利用2013年芦山M_S7.0级地震同震GPS数据反演了芦山断层几何与断层滑动分布，结果表明：芦山地震发震断层具有南陡北缓、上陡下缓的特征，低倾角的区域位于发震断层北段且靠近映秀断层的一侧；滑动分布模型的最大滑动量为0.82 m，其深度为13.67 km与小震发生集中平均深度12.5 km接近.我们选取1998-2014年龙门山断裂带区域地壳形变观测数据，拟合获得了龙门山断裂带走向方向上的速度分量，发现在汶川M_S8.0地震与芦山M_S7.0地震之间宽度约30 km破裂空区，龙门山断裂带西南段与东北段的形变分量以破裂空区为界方向相反.断裂带东北段（汶川地震主要发震断层）的形变分量方向与断层右旋走滑运动方向一致，而在断裂带西南段（芦山地震发震断层）的形变分量方向与断层左旋走滑运动方向一致.芦山地震走滑方向与汶川地震走滑方向相反是因为该断裂带构造运动在特有几何构造下受青藏高原东南向挤压，遇龙门山中段岩石圈楔状构造的阻挡，在汶川M_S8.0地震与芦山M_S7.0地震间的地震空区，形成了构造运动向其两侧分流的结果.
关键词: 汶川地震/
芦山断层/
断裂带形变/
GPS反演滑动分布/
库伦应力

Abstract:In this paper, the Lushan fault geometry and the fault slip distribution are inverted using co-seismic GPS data of the 2013 Lushan M_S7.0 Earthquake.The results show that the Lushan fault is steep in south and upper and gentle in north and lower. Its low-dip portion is located in the northern section of the Lushan earthquake fault and close to the and the side near the Yingxiu fault. The maximum slip of the sliding distribution model is 0.82 m at depth 13.67 km close to the average depth 12.5 km of small events. We select the crustal deformation field data of the Longmenshan fault zone from 1998 to 2014 to calculate the deformation component along the direction of the fault strike by fitting. The 30 km seismic gap between the Wenchuan earthquake and the Lushan earthquake is defined as a boundary. In the Longmenshan fault zone, the direction of the deformation component of the southwestern segment is opposite to that of the northeastern segment. While in the Wenchuan earthquake fault, the direction of the deformation component is consistent with that of dextral strike-slip of the fault, whereas in the Lushan earthquake fault, the direction of the deformation component is consistent with that of the left-lateral strike-slip movement of the fault. The striking direction of the Lushan earthquake is opposite to that of the Wenchuan earthquake, because the former is extruded to the southeast by the Tibetan Plateau under the unique geometric structure, which is blocked by the wedge-shaped structure of the lithosphere in the middle section of the Longmenshan. In the seismic gap between the Wenchuan M_S8.0 earthquake and the Lushan M_S7.0 earthquake, the tectonic movement diverges towards either side.
Key words:Wenchuan earthquake/
Lushan fault/
Fracture zone deformation/
Inversion sliding distribution with GPS/
Coulomb stress



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