1970年云南通海地震同震形变和破裂滑动初步研究结果  

Preliminary Study Result of the Coseismic Deformation and Rupture Slip of the 1970 Tonghai Earthquake,Yunnan Province

作　　者：谭凯[1] 王琪[2] 余建胜[1] 聂兆生[1] 邵德盛[3] 张彩红[1] 

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430071 [2]中国地质大学(武汉)地球物理与空间信息学院,武汉市430074 [3]云南省地震局,昆明市650041

出　　处：《大地测量与地球动力学》2017年第4期331-334,354,共5页Journal of Geodesy and Geodynamics

基　　金：中国地震局地震研究所所长基金(IS201506220);中国地震局地震行业科研专项(201208006);国家自然科学基金(40974012,41304019)~~

摘　　要：分别以三角测量获取的同震形变、GPS与三角测量联合获取的同震形变为约束,先采用模拟退火算法反演1970年通海地震单断裂矩形断层破裂模型,然后用约束变量的最小二乘法反演地震滑动分布模型。根据两套数据用模拟退火算法获得的单矩形断裂模型的倾角都超过80°,破裂长度都接近100km,破裂出露地表,以走滑为主。根据两套数据用约束变量的最小二乘法反演获得的两个破裂滑动分布模型,矩震级Mw=7.4,最大破裂位置和破裂深度大致相同,西北段破裂分布比较接近,而东南段差异较大。根据GPS和三角测量确定的东南段破裂滑动较大,可能是根据GPS和三角测量计算同震变形时,由于没有坐标转换公共点而引入一些较大的误差;也可能是用三角测量计算同震形变时低估了断裂东南端的变形。With two coseismic deformation data sets as constraints, one gained from triangulation data and the other from GPS and triangulation data, the single rectangular fault model of the Tonghai earthquake in 1970 is inferred using a simulated annealing algorithm, and then the slip distribution is inferred using bounded varia- ble least square. The results show that, the length of the outcropping, mainly strike slipping rupture of the single rectangular fault inferred from simulated annealing algorithm,is approximately 100 km; its dipping an gle is greater than 80°. The positions and depths of maximum slip in the two slip distribution models inferred from bounded variable least square constrained by the two data sets are basically consistent, while slips in southeast section determined from GPS and triangulation data are larger. Maybe some large errors were intro duced by the absence of common stations in coordinate transformation, or the deformation in the southeast section is underestimated.

关 键 词：GPS 三角测量 通海地震 同震形变 地震破裂 

分 类 号：P315[天文地球—地震学]