Shallow Induced Seismicity in Sichuan, China: A Coupled Flow–Geomechanics Modeling Analysis
Session: Mechanisms of Induced Seismicity: Pressure Diffusion, Elastic Stressing and Aseismic Slip IV
Type: Oral
Date: 4/20/2021
Presentation Time: 06:30 PM Pacific
Description:
On 25 February 2019, an ML 4.9 (Mw 4.3) earthquake occurred in the Rongxian County, Sichuan, China, presumably related to hydraulic fracturing operations in the Weiyuan Shale Gas Field. The earthquake was located at a depth of ~1 km, which is extremely shallower than the typical locations of induced earthquakes. This peculiarity has attracted detailed investigations into the mechanism of the 2019 Rongxian ML 4.9 earthquake. Recently, Yang et al. (2020) and Wang et al. (2020) have suggested that the earthquake was triggered by reactivation of the Molin fault – located around the same depth as the mainshock – as a result of poroelastic stress change followed by the hydraulic fracturing operations. Nevertheless, the precise mechanism of the shallow earthquake still remains elusive. To shed light on the mechanism of the 2019 Rongxian earthquake, we conduct a computational analysis of the earthquake sequence based on a coupled flow–geomechanics model. Using the extended finite element method (XFEM), the computational model incorporates the full two-way coupling of fluid flow and geomechanical processes on faults as well as off-fault domains. The main findings from the numerical analysis will be discussed.
Presenting Author: Chong Liu
Student Presenter: Yes
Authors
Chong Liu Presenting Author chongliu@connect.hku.hk The University of Hong Kong |
Jinhyun Choo Corresponding Author jchoo@hku.hk The University of Hong Kong |
Fushen Liu fushenliu@zju.edu.cn Zhejiang University |
Hongfeng Yang hyang@cuhk.edu.hk The Chinese University of Hong Kong |
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Shallow Induced Seismicity in Sichuan, China: A Coupled Flow–Geomechanics Modeling Analysis
Category
Mechanisms of Induced Seismicity: Pressure Diffusion, Elastic Stressing and Aseismic Slip