联合珊瑚礁、InSAR和GPS数据研究所罗门俯冲带地壳形变

The 1 April 2007 magnitude, MW 8.1 Solomon Islands earthquake is unique in that involved the rupture of at least two subducting plates, and that land occurs 7 kilometers away to the trench on the hanging wall side. The occurrence of islands extremely proximal to the trench and nucleation of rupture allows for the collection of an unprecedented co-seismic deformation dataset from regional uplift and subsidence of coastal areas, which makes geodetic inversion possible. This proposal intends to strengthen our understanding of how earthquake conceives and occurs by studying crustal deformation associated with frequent and big Solomon Islands megathrust earthquakes, which finally could help us research big earthquakes in China well..This proposal will try to derive co-seismic, Post-seismic and inter-seismic crustal deformation fields respectively by combining coral reef vertical displacement, InSAR and GPS data. Dip angle and slip distribution on rupture plane will be inverted under a wholly Bayesian framework with derived crustal deformation fields as constraints. Stress and strain fields on rupture plane are simulated with numerical manifold method. Coulomb stress trigger associated with Solomon Islands earthquakes is studied. And the potentially seismogenic area along Solomon Islands subduction zone is estimated by researching stress trigger and geological structure.

所罗门群岛俯冲带地震罕见地发生在三个板块的交界处，跨海沟两侧相距7公里的海岛提供了难得的获取大地测量数据的机会，使得用大地测量数据为约束进行大地测量反演成为可能，本项目拟通过研究地震频繁、震级大的所罗门俯冲带地震来进行地壳形变、大地测量反演及其动力学的研究，以深化对地震的孕育、发生和致灾机理的认识，从而为推进我国地震预测预报研究水平不断走向深入打下坚实的基础。.本项目联合珊瑚礁、InSAR和GPS数据建立所罗门群岛俯冲带地震的同震、震后和震间形变场；以获得的形变数据为约束，基于位错理论在全贝叶斯框架内反演断层倾角和断层面上的精细滑动分布；研究震后和震间形变模型；利用数值流形方法模拟断层面上的应力、应变分布；研究地震序列的库仑应力触发；结合所罗门群岛俯冲带的地质构造，评估所罗门群岛俯冲带的地震危险性，定位未来潜在强震高危区。

本项目对地震频繁、震级大的所罗门群岛地震进行了地壳形变和大地测量反演研究。利用2007年所罗门地震的珊瑚礁垂直形变数据、InSAR数据以及地震波数据对该地震的断层几何结构和滑动分布进行了研究；在贝叶斯框架下研究了该地震单一断层面的倾角和滑动分布；对2007年所罗门群岛地震的两段断层结构模型进行了研究；基于2007和2010年地震的滑动分布模型研究了2007年地震对2010年地震的应力触发关系，以及俯冲带上的库仑应力变化；结合历史地震背景评估了该区域潜在地震危险。.本项目对相关数值计算方法进行了深入研究。提出了融合InSAR和GPS数据来提取地表三维形变的ABIC方法和ESISEM方法；对InSAR时间序列及其在震间形变应用进行了研究；提出了利用jRi准则确定断层破裂面倾角的方法；构建了库仑应力误差模型并研究了库仑应力转移。