Dynamic Rupture Simulation of the 1833 Songming, Yunnan, China, M 8.0 Earthquake: Effects From Stepover Location and Overlap Distance

Yu, Houyun1,2; Hu, Feng3; Xu, Jiankuan1,4; Zhang, Zhenguo2,4; Chen, Xiaofei1,2,4

2022-02-01

10.1029/2021EA002100

EARTH AND SPACE SCIENCE   影响因子和分区

2333-5084

Stepover structures are widely distributed in natural fault systems. The jump distance is typically easier to identify than both the stepover location and the overlap distance because of the presence of lakes and sedimentary basins around the stepover. Using the curved grid finite-difference method, we first conducted a 3D spontaneous dynamic rupture simulation of the 1833 Songming earthquake on a continuous model of the western Xiaojiang fault to estimate the regional stress azimuth. Then, we performed rupture process simulations with different stepover structure models on the western Xiaojiang fault to investigate the effects of the stepover location and overlap distance on the dynamic rupture process. In addition, we analyzed the fault strength ratio S and rupture velocity of the preferred fault models and discussed the occurrence of supershear rupture during the Songming event. Finally, we simulated the strong ground motion with the preferred fault models for the 1833 Songming earthquake. Our simulation results suggest that the optimal regional maximum principal stress azimuth during the Songming event was N20 degrees W. Our simulations further reveal that the Qingshuihai stepover is located in the middle of Qingshuihai Lake, and the overlap distance is 6 km; in contrast, the location of the Yangzonghai stepover is located in the southern part of Yangzonghai Lake, and the overlap distance is not constrained. Furthermore, our numerical simulation indicates that the Songming earthquake exhibited supershear rupture; however, this supershear rupture is not sustained and is easily affected by the friction parameters and nucleation location.

SCI

英语

通讯

National Key R&D Program of China[2018YFC1503400] ; Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0203] ; National Natural Science Foundation of China[41922024,42174060,41790465,42074049] ; Shenzhen Science and Technology Program[KQTD20170810111725321]

Astronomy & Astrophysics ; Geology

Astronomy & Astrophysics ; Geosciences, Multidisciplinary

WOS:000763473900013

AMER GEOPHYSICAL UNION

Web of Science

1.Soutnern Univ Sci & Technol, Acad Adv Interdisciplinary Studies, Shenzhen, Peoples R China
2.Soutnern Marine Sci & Engn Guangdong Lab Guangzho, Guangzhou, Peoples R China
3.Univ Sci & Technol China, Sch Earth & Space Sci, Hefei, Peoples R China
4.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen, Peoples R China

Yu, Houyun,Hu, Feng,Xu, Jiankuan,et al. Dynamic Rupture Simulation of the 1833 Songming, Yunnan, China, M 8.0 Earthquake: Effects From Stepover Location and Overlap Distance[J]. EARTH AND SPACE SCIENCE,2022,9(2).

Yu, Houyun,Hu, Feng,Xu, Jiankuan,Zhang, Zhenguo,&Chen, Xiaofei.(2022).Dynamic Rupture Simulation of the 1833 Songming, Yunnan, China, M 8.0 Earthquake: Effects From Stepover Location and Overlap Distance.EARTH AND SPACE SCIENCE,9(2).

Yu, Houyun,et al."Dynamic Rupture Simulation of the 1833 Songming, Yunnan, China, M 8.0 Earthquake: Effects From Stepover Location and Overlap Distance".EARTH AND SPACE SCIENCE 9.2(2022).