摘要
航片解译及野外地震地质考察结果表明 ,鲜水河 -安宁河断裂带磨西 -冕宁段存在明显的晚第四纪活动性 ,其以左旋走滑运动为主 ,并伴有显著的垂直滑动分量。晚第四纪以来的平均水平滑动速率在鲜水河断裂磨西以南段为 6 0～ 9 9mm a ,安宁河断裂冕宁以北段为 4 7～5 3mm a。同震位错及地震地表破裂研究表明 ,A .D .1786年康定 -泸定磨西 7 级地震的地表破裂可能南延至田湾以南 ;安宁河断裂冕宁以北段则具有蕴育 7 级左右地震的构造背景 ,最晚一次强震的地质记录极有可能是史料记载不全的A .D .132 7年一次 6级或 6级以上地震的证据。
The results from interpretation of aerophotos and seismogeological research at the sites show that there are some obvious late-Quaternary activities on the Moxi\|Mianning segment along the Xianshuihe\|Annignhe fault zone,with the characteristics of sinistral\|slip movement accompanied by some significant vertical slip components.Since late\|Quaternary,the average horizontal slip rate of the segment at the south of Moxi along the Xianshuihe fault is 6\^0～9\^9mm/a and 4\^7～5\^3mm/a on the segent at the north of Mianning along the Anninghe fault.The results from the investigation of coseismic-slip and ground rupture show that the ground rupture caused by 1876 Kangding-Luding earthquake with M 73/4 can extend to the south of Tianwan.The segment at the north of Mianning in the Anninghe fault has a capability of producing M 7.5 earthquake and the geological record of the last strong earthquake must be the proofs of 1327 earthquake with M >6\^0 with poor historical records.
出处
《中国地震》
CSCD
北大核心
2001年第3期253-262,共10页
Earthquake Research in China
基金
地震科学联合基金(95 0 7 0 42 5 )资助
