汶川8.0级地震前后龙门山断裂活动特征浅析  

PRELIMINARY STUDY ON MOTION CHARACTERISTICS OF LONGMENSHAN FAULT BEFORE AND AFTER Ms8.0 WENCHUAN EARTHQUAKE

作　　者：焦青[1] 杨选辉[1] 许丽卿[1] 王博[1] 

机构地区：[1]中国地震局地壳应力研究所,北京100085

出　　处：《大地测量与地球动力学》2008年第4期7-11,37,共6页Journal of Geodesy and Geodynamics

基　　金：中国地震局地壳应力研究所基本科研业务专项(重点)项目(ZDJ2007-6)

摘　　要：利用跨龙门山断裂的流动短水准观测资料分析了汶川地震前后各测点的变化特征。分析认为:1)汶川地震前(2006年)跨断层短水准观测到了龙门山断裂的活动,且在震前均出现不同程度的加速活动特征;2)震前龙门山断裂中南段为逆断层活动,地表变形呈反"S"型;3)跨断层位移测量反映了汶川地震区域地表应力集中、释放的时空演化过程,且机理解释与震源机制解基本一致。In this paper by utilizing the mobile short-line leveling data across the Longmenshan fault the variation characteristics at each observation site before and after the Wenchuan earthquake are analyzed. By analyzing the motion type and stress pattern of the Longmenshan fault we investigated the seismogenic process and mechanism of the earthquake. The preliminary results are as follows, a） Before the Wenchuan earthquake the cross-fault short- line leveling in 2006 showed the activity at all of the stations of Longmenshan fault with a characteristic of accelerative movement to different degrees, b） Before the earthquake the short-line leveling indicated that the middle-south segment of Longmenshan fault showed reverse faulting movement, and the fault deformation was of inversive ＂S＂ type. c） Before and after the Wenchuan earthquake the cross-fault displacement measurements reflected the spatialtemporal evolution of the accumulation and release of regional surface stress, the interpretation of their mechanism is basically consistent with the focal mechanism solution.

关 键 词：汶川地震 龙门山断裂 跨断层位移 孕震机理 水准测量 

分 类 号：P315.725[天文地球—地震学]