运用SDM方法研究2001年昆仑山口西MS8.1地震破裂分布:GPS和InSAR联合反演的结果  

Slip model of the 2001Kunlun mountain M_S8.1 earthquake by SDM:joint inversion from GPS and InSAR data

作　　者：屠泓为[1,2] 汪荣江 刁法启[3] 张勇[4] 万永革[5] 金明培[6] 

机构地区：[1]青海省地震局,西宁810001 [2]德国地学研究中心(GFZ),德国波茨坦14473 [3]中国科学院测量与地球物理研究所,动力大地测量学重点实验室验室,武汉430077 [4]北京大学地球与空间科学学院,北京100871 [5]防灾科技学院,北京燕郊101601 [6]中国地震局滇西地震预报实验场办公室,云南大理671000

出　　处：《地球物理学报》2016年第6期2103-2112,共10页Chinese Journal of Geophysics

基　　金：中国地震局星火计划(XH16039);人社部择优计划项目;地震行业专项(201408023);国家留学基金联合资助

摘　　要：2001年11月14日昆仑山口西MS8.1地震是有现代仪器记录以来发生在青藏高原区域最大地震之一,对研究青藏高原的运动学模式具有重要意义.从地震发生至今,不同研究者运用不同资料和方法获取的地震破裂分布还存在一定差异.基于此,本文采用GPS和InSAR资料数据,参考最新研究成果,构建更为合理的断层几何模型,运用SDM方法反演本次地震的破裂分布.在反演中充分考虑不同数据权重的影响及InSAR数据中存在的整体偏移.结果显示本次地震断层性质以左旋走滑为主,最大破裂位错为-6.9m,分布在35.76°N、93.40°E附近,地震较大破裂区域主要分布在地下20km以内.同时,反演的位错分布在断层浅部与地质考察得到的地表破裂分布较为吻合.在与前人相关研究的对比中,显示本文结果的可靠性是较高的,例如,近地表破裂包络线与地表考察结果相近,地下破裂分布特征与前人提出的3次子地震事件相一致等,再一次佐证了此次地震由多次子地震事件组成的研究结论.For the 2001 MS8.1Kunlun earthquake,which was one of the largest events occurredaround the Tibet plateau,a large controversy still exists about its rupture detail.In this paper,we invert the co-seismic GPS and InSAR data for a robust finite-fault model of the Kunlun earthquake based on a realistic fault geometry buried in a layered earth structure.The inversion is based on the constrained least-squares principle and realized using the steepest decent method（SDM）.The different data sets are weighted according to their variance and spatial coverage.The results show that the slip maximum can reach up to -6.9mand is located at 35.76°N and93.40°E.The main rupture area is located at the shallow depth above 20 km.The inverted shallow slip agrees with the surface rupture observed by the field survey,and the whole slip pattern appears generally consistent with the results obtained from previous geological and seismic wave studies.

关 键 词：昆仑山口西MS8.1地震 破裂分布 位错反演 

分 类 号：P315[天文地球—地震学]