2022年芦山Ms6.1地震应力触发及地震危险性分析
Stress Triggering and Seismic Hazard Assessment of the 2022 Lushan Ms 6.1 Earthquake
肖阳 1单斌 1刘成利 1周万里1
作者信息
- 1. 中国地质大学地球物理与空间信息学院地球内部多尺度成像湖北省重点实验室,湖北武汉 430074
- 折叠
摘要
2022年6月1日,四川芦山县地区发生了Ms6.1地震,造成4死14伤以及周围地区多县经济损失.考虑到地区丰富的断层背景、历史地震以及地震空区,对该地区重要历史地震序列的回溯研究以及未来危险性评估对防震御灾具有重要意义.基于弹性位错理论以及地区岩石圈分层模型,计算了Mw7.9汶川地震以及Ms7.0芦山地震对本次地震在不同深度上的同震及震后粘弹松弛效应影响,讨论历史地震对本次地震发生的影响.同时,对未来十年该地区及周边活跃断层的应力积累进行计算,圈定未来地震危险性较高的区域.结果表明:(1)Mw7.9汶川地震导致2022年Ms6.1芦山地震震中的同震应力增量为0.014 MPa,可能有效的促进了芦山地震的发生,而Ms7.0芦山地震的发生导致其应力释放0.174 MPa,起到抑制作用.考虑到震后粘弹松弛的影响,本次地震震中发震前应力积累为0.086 MPa,已恢复到较高应力水平,具备发震背景;(2)大邑地震空区中段、抚边河断裂带未来库仑应力增量进一步提升,地震危险性较强.
Abstract
On June 1,2022,an earthquake of magnitude 6.1 occurred in Lushan,Sichuan,causing 4 deaths,14 injuries and economic losses in many surrounding counties.This region is characterized by a dense fault system and intense historical earthquakes,as well as a seismic gap that receives much attention,so a retrospective study of major historical earthquake sequences and their impacts on seismic risks in the region is of great significance for seismic hazard mitigations in the future.Based on the elastic dislocation theory and the regional lithosphere layered model,this paper calculates the co-seismic and post-earthquake viscoelastic relaxation effects of the Mw7.9 Wenchuan earthquake and the Ms7.0 Lushan earthquake on the epicenter of the 2022 earthquake at different depths,and discusses the impacts of historical earthquakes on the occurrence of this earthquake.Moreover,stress accumulation on active faults in the area and surrounding areas in the next ten years is calculated to delineate areas with high seismic risk in the future.The results show that:(1)The Mw7.9 Wenchuan earthquake resulted in a stress increment of 0.014 MPa at the epicenter of the 2022 Ms6.1 Lushan earthquake,which may have effectively promoted the occurrence of this earthquake,while the Ms7.0 Lushan earthquake caused a stress release of 0.174 MPa,which delays the occurrence of the 2022 earthquake.Considering the influence of viscoelastic relaxation after the 2008 and 2013 earthquakes,stress increment of the epicenter is 0.086 MPa,which has already recovered to a higher stress level before its occurrence.(2)The Coulomb stress increment in the middle section of the Dayi seismic gap and the Fubianhe fault zone will further increase in the future,and so doesthe seismic risk.
关键词
芦山地震/汶川地震/地震应力触发/地震危险性/库仑应力/地震学Key words
Lushan earthquake/Wenchuan earthquake/stress triggering/seismic hazard/Coulomb stress/seismology引用本文复制引用
基金项目
国家重点研发计划项目(201YFC1500302)
国家自然科学基金(41674106)
出版年
2024
NETL
NSTL
万方数据