汶川震后龙门山周边活动地块构造变形及断裂活动  

Tectonic Deformation and Fault Activity of Active Blocks in Longmenshan and Surrounding Area after Wenchuan Earthquake

作　　者：熊维[1,2] 谭凯[1,2] 乔学军[1,2] 王伟[1,2] 

机构地区：[1]中国地震局地震研究所(地震大地测量重点实验室),武汉市洪山侧路40号430071 [2]中国地震局地壳应力研究所武汉科技创新基地,武汉市洪山侧路40号430071

出　　处：《大地测量与地球动力学》2015年第5期758-763,共6页Journal of Geodesy and Geodynamics

基　　金：中国地震局地震研究所所长基金(IS201456148;IS201506220);中国地震局地震行业科研专项(201208006);国家自然科学基金(40974012)

摘　　要：利用1999~2013陆态网络观测资料,计算汶川地震前后龙门山地区周边活动地块应变率场分布及欧拉旋转矢量,基于Okada矩形位错模型,反演块体边界主要断层活动性状,分析研究区域现今构造变形和应变分配,并讨论汶川地震对上述过程的影响。研究表明,巴颜喀拉东部、川西北、滇中等活动地块向南东向运移的同时自身作顺时针旋转;由于龙门山断裂、丽江-小金河断裂等逆冲带对地壳应变的吸收与调整,研究区域地壳变形由西向东逐渐减弱,区域地壳变形以连续渐变为主要特征;汶川地震使巴颜喀拉块体、川西北块体的南东向运移加速,并增强了安宁河-则木河-小江断裂带左旋走滑运动和丽江-小金河断裂的逆冲运动。Based on GPS velocity field data from 1999 to 2013,we calculate the train rate field and the Euler rotation vector of main blocks in Longmenshan and the surrounding area.Using these results as constraints,we calculate the slip rate and locking depth of the main active faults with the Rngchn program based on the Okada model,and then discuss regional tectonic deformation and strain distribution in the research area.Finally,we analyze the effect of the Wenchuan earthquake on the above process.The research shows that：most active blocks,such as east Bayan Har,northwest Sichuan and middle Yunnan,are moving to the southeast with a clockwise rotation at the same time.Due to the crustal strain absorption and adjustment of thrust belts such as the Longmenshan fault,the regional crustal deformation decreases gradually from the west to the east.The Wenchuan earthquake not only accelerated the motion of Bayan Har and northwest Sichuan block,but also enhanced the strike-slip and thrust movement of the Anninghe-Zemuhe-Xiaojiang fault and the Lijiang-Xiaojinhe fault.

关 键 词：汶川地震 活动地块 断层滑动速率 构造变形 

分 类 号：P315[天文地球—地震学]