汶川地震断层滑动模型反演及地震区域构造的大地测量约束  

Inversion of the Slip Model of Wenchuan Earthquake and the Geodetic Constraints of the Regional Structure

作　　者：邓明莉[1,2] 孙和平 徐建桥[1] 

机构地区：[1]中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室,武汉市徐东大街340号430077 [2]中国科学院大学地球科学学院,北京市玉泉路甲19号100049

出　　处：《大地测量与地球动力学》2015年第6期969-973,978,共6页Journal of Geodesy and Geodynamics

基　　金：国家重大基础研究计划(2014CB845902);国家自然科学基金(41321063;41274085)

摘　　要：以汶川地震前后GPS观测得到的同震形变场为约束,利用带约束的最小二乘反演方法,分别反演考虑与不考虑滑脱层的最优同震断层滑动模型,并在此基础上正演了同震重力变化。结果表明,含滑脱层的断层滑动模型模拟的GPS台站的同震水平形变和重力台站的同震重力变化都更接近实际的观测结果,证实龙门山的中央断裂带南段存在大规模的近水平的滑脱层参与了汶川地震的同震滑动。By using the least-square method constrained by the co-seismic deformations of the Wen- chuan earthquake derived from GPS, we inverse the slip models, with and without considering ramp- decollement separately. Based on the slip models obtained, we simulate the co-seismic gravity chan- ges. The results show that the co-seismic horizontal deformation of the GPS stations and the gravity changes of the gravity stations modeled by the slip model with ramp-decollement are both closer to the actual measurements. This verifies that a large-scale nearly horizontal ramp-decollement,which exis- ted at the southern part of the mid-fracture of the Longmenshan, has participated in the co-seismic slip of Wenchuan earthquake.

关 键 词：汶川地震 滑脱层 断层滑动模型 同震形变 同震重力变化 

分 类 号：P315[天文地球—地震学]