汶川8.0级地震前断层形变异常及与其它大震的比较  

Anomalous change of fault deformation before Wenchuan M_S8.0 earthquake and its comparison with response of other large earthquakes

作　　者：周硕愚[1] 吴云[1] 施顺英[1] 陈志遥[1] 

机构地区：[1]中国地震局地震研究所,中国武汉430071

出　　处：《地震学报》2009年第2期140-151,共12页Acta Seismologica Sinica

基　　金：中国地震局地壳形变动态图象提取与强震预测技术研究项目(2006BAC01B0202);中国地震局"十二五"发展规划研究项目;中国地震局地震研究所科技发展基金项目(IS200861355);中国地震局老专家科研基金(2009汶川地震地形变与地震预测)项目资助

摘　　要：用蕴震系统信息合成和地壳形变图象动力学参量方法,对龙门山、鲜水河、安宁河断裂带69条跨断层形变观测时序(1997年1月—2008年1月)整体地作了数据处理,发现龙门山断裂带在汶川MS8.0地震前出现了整体活动强度增高(加速度运动)、突跳异常丛集和近震中断裂的快速滑动.汶川8.0级与唐山7.8级及丽江7.0级地震之前的断层形变异常具有相似性,呈现出一定的可重现性,但前者的异常强度偏低.用系统自组织理论、断裂力学、静地震、慢地震、蠕滑、亚板块挤压与深部物质向上运移的共同作用能初步解释这些异常现象.Using the method of information synthesis of seismogenic system and pattern dynamic parameter analysis of crustal deformation, we analyzed as a whole 69 time series of across fault deformation observed during January 1997 to January 2008 in the Longmenshan, Xianshuihe and Anninghe fault zone. The result shows that fault deformation in Longmenshan fault zone revealed anomalies before Wenchuan Ms8.0 earthquake, including overall accelerated fault motion,frequent jump of fault displacement and fast sliding of the faults close to the earthquake epicenter. Comparing the preseismic fault deformation anomalies of Wenchuan Ms8.0 with that of Tangshan Ms7.8 and Liiiang Ms7. 0 earthquake, they show similarity and repeatability, except for that the anomalous deformation before Wenchuan Ms8.0 earthquake is a little weak. The deformation anomalies may be preliminarily explained with self-organization theory of nonlinear system, faulting mechanics, slow earthquakes, silent earthquakes, creepage and the joint action of subplate extruding and material upward transporting due to deep flow.

关 键 词：汶川8.0级地震 龙门山断裂带 断层形变 震前形变 震前滑动 

分 类 号：P315.725[天文地球—地震学]