地质力学学报2024，Vol.30Issue(3)：443-461,19.DOI:10.12090/j.issn.1006-6616.2023038
2022年6月10日四川马尔康MS6.0震群同震地质灾害发育特征及其控制因素分析
Analysis of the development characteristics of co-seismic geological hazards and their controlling factors in the Maerkang MS 6.0 earthquake swarm,Sichuan,on June 10,2022
摘要
Abstract
[Objective]This study aims to reveal the distribution patterns and characteristics of co-seismic geological hazards in earthquake swarms,clarify the differences in induced geological hazards by different types of earthquakes,further understand the seismic risks around and within the Bayan Har Block,and provide efficient guidance for the prediction and prevention of secondary geological hazards induced by earthquakes.[Methods]We take the co-seismic geological hazards of the Maerkang MS 6.0 earthquake swarm in 2022 as the research focus.Through systematic data and results analysis on earthquake swarm sequence,regional tectonic environment,regional crustal deformation,and post-earthquake short-term geological hazard,the regional and deep structural environment of the Maerkang MS 6.0 earthquake swarm and the main controlling factors of co-seismic geological hazards are revealed.[Results]The results show that the Maerkang MS 6.0 earthquake swarm is a deep-seated sticky-slip earthquake that occurred on a secondary fault in the active strong earthquake zone within the Bayan Har block,a region with extremely strong peripheral boundary activity.The earthquakes with similar magnitudes may be the result of ruptures of secondary faults of the Songgang fault and the successive ruptures of the barriers between them.The earthquake has resulted in 83 newly discovered geological hazard risks,exacerbating deformation in 106 existing hazard spots and triggering multiple high-altitude landslides and a series of fractured mountain slopes.The areas of extreme,high,and medium geological hazard risk in Caodeng Town,the epicenter area after the earthquake,account for 1.62%,4.80%,and 12.37%,respectively.The occurrence of secondary geological hazards following earthquakes exhibits a positive correlation with the earthquake magnitude,with the number increasing linearly as the magnitude rises.[Conclusion]The significant differences in the GPS horizontal velocity field and vertical velocity field on both sides of the Darlag-Songgang-Fubianhe fault zone are key factors contributing to the activity of this fault and triggering the recent earthquake.The main controlling factors of co-seismic geological hazards induced by earthquakes are,from primary to secondary,the ruptured fault and its associated faults,seismic magnitude and energy attenuation,terrain slope and altitude difference,and rock mass structure and density of structural surfaces.[Significance]This study predicts a high risk of future strong earthquakes in the intersection area of the Songgang fault,which triggered this earthquake,and the Longriba active fault.The surrounding area of the seismogenic fault and its associated faults are at a high risk of geological hazards during earthquakes.The findings provides a reference for predicting and controlling the risk of co-seismic geological hazards in this area.关键词
马尔康地震/地震构造/松岗断裂/同震地质灾害/青藏高原东缘/巴颜喀拉地块Key words
Maerkang earthquake/seismotectonics/Songgang fault/coseismic geological hazard/eastern margin of the Tibetan Plateau/Bayan Har block分类
天文与地球科学引用本文复制引用
孙东,覃亮,蒙明辉,杨涛,章旭,胡骁..2022年6月10日四川马尔康MS6.0震群同震地质灾害发育特征及其控制因素分析[J].地质力学学报,2024,30(3):443-461,19.基金项目
四川省自然科学基金项目(2023NSFSC0784) （2023NSFSC0784）
四川省科技计划项目(2023YFS0435)This research is financially supported by the Natural Science Foundation of Sichuan(Grant No.2023NSFSC0784)and the Sichuan Provincial Science and Technology Project(Grant No.2023YFS0435). （2023YFS0435）
