汶川8级大地震活动断裂滑动速率异常低的比较讨论  

Comparative Discussion of the Abnormal Low Slip Rate on the Active Fault of the Wenchuan M_S8.0 Earthquake

作　　者：傅征祥[1] 吕晓健[1] 金学申[2] 邵辉成[3] 戴英华[2] 郝平[1] 

机构地区：[1]中国地震局地震预测研究所,北京100036 [2]河北省地震局,河北石家庄050021 [3]陕西省地震局,陕西西安710068

出　　处：《地震》2010年第2期1-9,共9页Earthquake

基　　金：国家重点基础研究发展计划(973计划)项目(2008CB425703)

摘　　要：本文在收集1900—2008年东亚大陆西部三角地震区内8次陆内逆冲型浅源大地震（M≥7.5）活动断裂的滑动速率基础上,初步比较分析表明东亚大三角地震区陆内逆冲型孕震断层的缩短或垂直平均滑动速率≤12 mm/a;2008年四川汶川8.0级大地震发生在滑动速率异常低（0.2～1.0 mm/a）的龙门山活动断层上;地震震级大小和滑动速率大小之间的关系并没有显示出线性的简单相关关系;地震震级大小可能与多种因素有关,包括断层的地质年代、尺度（长度、宽度和深度）、活动速率和历史、物性,以及应力-应变本构关系和动力学环境等,需要深入研究。This paper comparatively discusses the active fault slip rates of 8 great intra-continental shallow thrust earthquakes occurred in the East Asia Triangular Seismic Region based on the collected slip rate data.Preliminary analysis shows that the average vertical slip or shortening rates on the shallow thrust faults are less than 12 mm/a in the region.The great Wenchuan MS8.0 earthquake of May 12,2008,Sichuan province,China,occurred in the Longmen Shan active fault with abnormal low slip rate（0.2～1.0 mm/a）.The relationship between earthquake magnitude and slip rate is not linear simply.Earthquake magnitude might be related to the geological ages,scale（length,width and depth）,rate and history,medium property,stress-strain relation and geodynamic condition of the earthquake faults,which needs further and deep study.

关 键 词：汶川8级大地震 断裂滑动速率 龙门山断裂带 东亚大三角地区 

分 类 号：P315.7[天文地球—地震学]