刘雷^1,,
李玉江^2,,,
朱良玉¹,
季灵运¹
1. 中国地震局第二监测中心, 西安 710054
2. 应急管理部国家自然灾害防治研究院, 北京 100085

基金项目: 国家自然科学基金项目（41874116，41904007），陕西省自然科学基础研究计划项目（2021JQ-979），中国地震局地震科技星火计划项目（XH20083，XH20081Y）资助


详细信息

作者简介: 刘雷, 男, 1990年生, 工程师, 2016年毕业于长安大学, 主要从事地壳形变及构造动力学等方向的研究.E-mail:liulei41325@163.com

通讯作者: 李玉江, 男, 1982年生, 博士, 副研究员, 主要从事断层相互作用机制与地球动力学数值模拟方面的研究.E-mail:toleeyj@126.com

中图分类号: P553;P315

收稿日期:2021-03-25
修回日期:2021-06-01
上线日期:2021-07-10

Influence of the 1947 Dari M7.7 earthquake on stress evolution along the boundary fault of the Bayan Har block: insights from numerical simulation

LIU Lei^1,,
LI YuJiang^2,,,
ZHU LiangYu¹,
JI LingYun¹
1. The Second Crust Monitoring and Application Center, China Earthquake Administration, Xi'an 710054, China
2. National Institute of Natural Hazards, Ministry of Emergency Management, Beijing 100085, China


More Information

Corresponding author: LI YuJiang,E-mail:toleeyj@126.com

MSC: P553;P315

--> Received Date: 25 March 2021
Revised Date: 01 June 2021
Available Online: 10 July 2021


摘要
摘要:1947年达日7.7级地震是发生在巴颜喀拉块体内部的一次强震，该地震在块体边界断裂带应力演化中的作用，在以往的研究中多被忽略.本文通过构建巴颜喀拉块体东部及邻区三维黏弹性有限元模型，考虑达日地震的同震位错与震后黏弹性松弛效应，分析该地震的发生引起巴颜喀拉块体边界断裂带上的库仑应力变化.结果表明：达日地震除造成达日断裂破裂段两端相邻未破裂段显著的库仑应力增加外（>1.0×10⁶ Pa），同时造成龙日坝断裂中-北段、东昆仑断裂中西段、龙门山断裂中-北段、马尔康断裂、鲜水河断裂中-南段和甘孜—玉树断裂西段同震库仑应力的增加，最大达1.4×10⁴ Pa.相反，也造成东昆仑断裂中-东段、甘孜—玉树断裂中-东段、龙日坝断裂南段、鲜水河断裂北西段和龙门山断裂南段库仑应力的减小.达日地震的发生导致后续1955年康定7.5级地震、1963年阿兰湖7.0级地震和2008年汶川8.0级地震等强震震源处累积（同震+震后）库仑应力变化分别为3.58×10³ Pa、1.16×10⁴ Pa、7.68×10³ Pa.结合震间构造应力累积速率的结果，认为1955年康定、1963年阿兰湖和2008年汶川地震的发震时间分别提前了约13.4年、40.6年和49.5年.上述结果显示块体内部强震对相邻边界断裂带上应力演化的影响不可忽略.
关键词: 巴颜喀拉块体/
达日地震/
库仑应力变化/
有限元模拟/
地震危险性

Abstract:The 1947 Dari M7.7 earthquake occurred inside the Bayan Har block. The effect of this earthquake on the stress evolution of the block boundary fault zone has been mostly ignored in the previous studies. In this study, we construct a three-dimensional viscoelastic finite element model of the eastern Bayan Har block and its adjacent areas, and analyze the Coulomb stress change caused by the Dari earthquake on the block boundary faults, considering the co-seismic dislocation and post-seismic viscoelastic relaxation effects. The results show that the Dari earthquake not only causes the significant increase of Coulomb stress change (>1.0×10⁶ Pa) in the adjacent non-ruptured sections on both ends of the Dari fault but also causes the co-seismic Coulomb stress increases on the middle-north section of the Longriba fault, the middle western section of the East Kunlun fault, the middle-south section of the Longmen Shan fault, the Barkam fault, the middle-south section of the Xianshuihe fault, and the western section of the Garzê-Yushu fault, with the maximum reaches 1.4×10⁴ Pa. On the contrary, the co-seismic Coulomb stress decreases on the middle-east section of the East Kunlun fault, the middle-east section of the Garzê-Yushu fault, the southern section of the Longriba fault, the northwest section of the Xianshuihe fault, and the southern section of the Longmen Shan fault. Moreover, the combined (co- and post-seismic) Coulomb stress change induced by the Dari earthquake on hypocenters of the 1955 Kangding M7.5 earthquake, the 1963 Alan Lake M7.0 earthquake, and the 2008 Wenchuan M8.0 earthquake are 3.58×10³ Pa、1.16×10⁴ Pa and 7.68×10³ Pa, respectively. By integrating the accumulation rate of inter-seismic tectonic stress, we conclude that the 1955 Kangding earthquake, the 1963 Alan earthquake, and the 2008 Wenchuan earthquake are advanced by about 13.4、40.6 and 49.5 years, respectively. Our findings indicate the importance of strong earthquakes inside the block on the stress evolution on adjacent boundary fault zones.
Key words:Bayan Har block/
Dari earthquake/
Coulomb stress change/
Finite element model/
Seismic hazard



PDF全文下载地址:

http://www.geophy.cn/data/article/export-pdf?id=bff876f3-2b78-4935-b43c-5fdd27d100a1