汶川M_S8.0地震中央断裂北段地表破裂特征  

The Surface Rupture of the M_S8.0 Wenchuan Earthquake on the Northern Segment of Central Fault

作　　者：乔宝成[1] 李勇[1] 董顺利[1] 闫亮[1] 陈浩[1] 马博琳[1] 

机构地区：[1]成都理工大学地球科学学院,四川成都610059

出　　处：《西北地震学报》2009年第4期333-338,348,共7页Northwestern Seismological Journal

基　　金：国家自然科学基金(49803013;40372084;40841010);中国地质调查局应急项目;中石化前瞻性项目

摘　　要：研究了2008年汶川大地震的发震构造龙门山构造带的北段,即北川-南坝-林庵寺断裂的地表破裂。通过黄家坝、桂溪、平通、南坝、石坎子等地的考察和测量,显示该段地表破裂沿断裂带连续分布,走向为N45°～65°E。垂直位错与水平位错比值从西南段黄家坝的2.8:1逐渐降低到北东段南坝、石坎子的0.9:1。地表破裂特征表明,断裂以右旋走滑分量为主,并具有较高的逆冲分量。余震分布表明,青川断裂与北川-南坝-林庵寺断裂之间可能存在隐伏活动断裂。The Surface rupture of Beichuan--Nanba--Linanshi Fault, which is the northern seg- ment of Longmenshan tectonic belt is studied. Observation at Huangjiaba,Guixi, Pingtong, Nanba and Shikanzi suggests that the surface ruptures on this segment spread continuously along the trend of the fault with N45°-65°E in general. The rate of vertical offset and horizontal offset become small from Huangjiaba（2.8：1） to Shikanzi {0.9：1）. Features of surface rupture indicate that the fault movement is thrusts with dextral strike-slip. Distribution of aftershocks indicates that the area between Beichuan--Nanba--Linanshi Fault and Qingchuan Fault probably have a buried active fault.

关 键 词：汶川MS8.0地震 龙门山构造带 中央断裂 地表破裂 同震位移 

分 类 号：P315.2[天文地球—地震学]