用近场大地测量强化昆仑山地震破裂及区域流变结构研究

项目名称： 用近场大地测量强化昆仑山地震破裂及区域流变结构研究

项目编号： No.41274037

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 王琪

作者单位： 中国地质大学（武汉）

项目金额： 90万元

中文摘要： 2001年昆仑山八级地震是大陆地区观测到破裂最长的特大型走滑地震，并对此后十年大陆地震活动性产生深远影响。地震破裂是地壳弹性应变转化为永久性构造变形的重要环节，断层破裂模型是认识地震动力过程和震源机制的基础，震后地壳松弛变形是分析岩石圈流变结构的重要途径。然而，十年来基础资料仍比较欠缺，制约了破裂模型和流变结构研究的进一步发展。本项目将GPS和InSAR和传统测量结合，通过复测昆仑山地区三角控制网，以密集近场数据约束地震同震位移场, 建立精细滑动分布模型，研究昆仑山断层应力状态, 深部破裂特征及其断层地表几何结构的关系。 本项目还将延续震后十年GPS震后观测，并利用现有InSAR震后监测资料, 通过多种数值模拟算法, 约束昆仑山地区下部壳幔流变结构参数，研究藏北地区块体运动方式和岩石圈变形机制。研究成果将推进昆仑山与汶川地震的比较研究，深化对区域大震活动性的认识。

中文关键词： 昆仑山；同震形变；GPS；三角点；滑移分布

英文摘要： The Ms8.1 Kunlun Shan earthquake of 14 November 2001 ruptured a 400 km-long and more stretch of the sinistral strike-slip fault along the eastern Kunlun Shan located at the northern flank of the Tibetan Plateau Ranking as the largest strike-slip event ever documented instrumentally in Asia. It has exerted a significant impact on the regional seismicity in years to come. Earthquake rupture is a fundmental process in which elastic stresses localized on seismogenic faults give rise to irreversilbe tectonic deformation by abrupt faulting. Our understanding of this rare rupture requires a refined slip model that sheds detailed insights into how the tectonic stresses are accumulated and released on the seismogenic faults Unfortunately, previous works of slip models for the Kokoxili earthquake were hampered obviously by the facts that near-field data were insufficient and inaccuracy. We are proposing that such a drawback can be greatly overcome by reoccupying conventional geodetic network across the Kunlun Shan fault. Our slip model will be well constrained with the addition of denser near-field geodetic data and may help，with an unprecedented resolution, to understand why the rupture front propogated across neighbouring segments to grow into a great event for hundreds of kilometers. In this study, we focus on slip

英文关键词： Kunlun shan；Coseismic slip；GPS；triangulation network site；Slip distribution