川滇块体东边界活动断裂的大地震活动特征分析  

Analysis of Large Seismic Activity Characteristics of Active Faults at the Eastern Boundary of Sichuan-Yunnan Block

作　　者：廖程 梁明剑[1] 左洪 赵柯 LIAO Cheng;LIANG Mingjian;ZUO Hong;ZHAO Ke(Sichuan Earthquake Agency,Sichuan Chengdu 610041,China)

机构地区：[1]四川省地震局,四川成都610041

出　　处：《四川地震》2023年第3期1-8,共8页Earthquake Research in Sichuan

基　　金：四川省自然科学基金(2022NSFSC0211);四川省地震局地震科技专项(LY2314)资助.

摘　　要：活动断裂的活动习性是认识活动断裂应变加载及释放随时间、空间变化的关键所在,也是研究区域运动学、动力学和科学评价地震危险性的重要基础。安宁河断裂、大凉山断裂与鲜水河断裂呈倒“Y”字形交于石棉一带,共同协调了鲜水河断裂向SE的应变传递,2022年鲜水河断裂磨西段发生了泸定M_(S)6.8地震后,安宁河断裂和大凉山断裂的地震危险性再次引起了人们的关注。本文通过梳理分析这3条断裂相关的古地震和历史大地震资料,得出以下认识:①安宁河断裂和鲜水河断裂磨西段近4000 a来的大地震平均复发间隔约为700 a,大凉山断裂则为524 a;②鲜水河断裂磨西段和安宁河断裂的古地震活动表现为丛集特征,大凉山断裂的古地震活动则表现为准周期特征;③近4000 a来三条断裂在200 a时间窗内的大地震活动表现出准同步性,在时空上有相互影响的特征。The activity behavior of active faults is the key to understand the variation of strain loading and release in active faults with time and space,which is also an important basis for the study of regional kinematics and dynamics and scientific evaluation of seismic risk.The Anninghe fault,Daliangshan fault and Xianshuihe fault intersect in the asbestos-area in a“Y”shape,accommodating the strain transfer of the Xianshuihe fault to SE.After the Luding 6.8 earthquake occurred along the west section of the Xianshuihe fault in 2022,the seismic risk of the Anninghe fault and Daliangshan fault once again have attracted attention.By combing and analyzing the data of ancient earthquakes and historical strong earthquakes related to the three faults,the following conclusions are obtained:①The average recurrence interval of major earthquakes in the Anninghe and Moxi section in the past 4000 years is about 700 a,and that of the Daliangshan fault is about 500 a;②The paleoseismicity of Moxi and Anninghe faults is clustered,while that of Daliangshan fault is quasi-periodic.③The large seismic activity of the three faults in the past 4000 years in the 200 a time window shows quasi-synchronization,which are characteristics of mutual influence in time and space.

关 键 词：川滇块体 古地震 活动特征 鲜水河断裂 安宁河断裂 大凉山断裂 四川泸定M_(S)6.8地震 

分 类 号：P315.2[天文地球—地震学]