1920年海原大地震与构造关系的讨论  

A DISCUSSION ON RELATIONSHIP BETWEEN THE 1920 HAIYUAN M_S8.6 EARTHQUAKE,NORTHWEST CHINA AND GEOLOGIC STRUCTURE

作　　者：向光中[1] 

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000

出　　处：《西北地震学报》2001年第1期92-98,共7页Northwestern Seismological Journal

基　　金：中国地震局兰州地震研究所论著!编号:LC2 0 0 10 11

摘　　要：根据人工地震、重力、地质、航磁、大地电磁测深、地震活动及地球化学资料 ,研究了 1 92 0年海原大地震与构造的关系 .结果表明 :海原断层实际是深度不超过 1 0km的铲状逆掩推覆断层 ,而海原大震的震源深度为 1 5～ 2 0km ,因此 ,海原断层与该次大震的发生无关 .海原大地震的发生既与延至软流层顶部的近NS向和近EW向的构造有关 ,也与软流层的物质活动有关 .Data of artificial earthquake sounding,interpretation of gravity,geology,aeromagnetic detection,telluric electromagnetic sounding,seismic activity and geochemistry are used to study relationship between the 1920 Haiyuan M S8.6 earthquake and geologic structure.The result shows that the Haiyuan fault is an overlap fold fault taking the shape of the shovel with depth less than 10 km,which bears no relation to occurrence of the 1920 Haiyuan earthquake because the focal depth of the earthquake is 15～20 km.The Haiyuan earthquake relates to both NS and EW structures extending to the top of the asthenosphere and the movement of the material of the asthenosphere.The ground deformation of all kinds along the Haiyuan fault are induced by the earthquake.

关 键 词：宁夏 海原地震 地震断层 成因 东西向构造 南北向构造 环形构造 

分 类 号：P315.2[天文地球—地震学]