断层面形貌几何特征与破裂过程的相关性研究

地震学家根据地震滑动位移分布推断断层面上存在与破裂过程相关的"凹凸体"或"障碍体"。那么，这些"凹凸体"或"障碍体"究竟是什么? 具有什么样的地质意义? 是断层面上确实存在的几何构造体，还仅仅是一种力学状态的差异? 又与破裂带的几何结构之间存在什么样的联系? 本项目将在"高精度断层面形貌学定量研究（40872128）"的基础上，开展地震破裂带几何结构特征与同震位移分布的相关性研究；结合失稳摩擦实验，研究失稳摩擦面微形貌特征与失稳滑动过程中的应力、应变场和微破裂分布的相关性，并分析破裂面形貌特征对破裂过程的影响和控制。最终，根据破裂面宏观形貌与破裂分布相关性和破裂面微观形貌与破裂过程相关性的研究结果，探索"凹凸体"或"障碍体"的地质意义，以及与破裂带地表几何结构之间的联系。

"Asperity" or "obstacle" on a fault surface in deep, which controls and affects the all rupture process, has been deduced from the pattern of co-seismic displacements on fault surface. Then, what is the asperity or obstacle? What geologic implication does it have? Is it a real geometric structure, or only different stress field on the fault? What relationship between the "asperity" or "obstacle" and the geometrical features of the rupture zone on surface is there? To resolve these problems and understand "asperity" or "obstacle" deeply, a further study on the "relationship between morphologic characteristics of a fault surface and rupture process" should be done. First, using the study methods and mathematic models achieved in "study on high-resolution digital topography of fault surface (40872128)", we will calculate the roughness of a surface rupture and the co-seismic displacements along the rupture, and analyze their relevance. Second, combined with the experiment of stick sliding, we will study the relationship between the topographic features of the friction surface and the stress and strain field, micro-fracture distribution in unstable sliding process, and analyze how does the topographic features of the friction surface control and affect the unstable sliding based on the analysis of the topographic features of the friction surface, stress and strain field, micro-fracture distribution in different sliding stages. Finally, based on these results, we will probe the geologic implication of the "asperities" or "obstacles", and the relationship between the geometric features of a surface rupture and the "asperities" or "obstacles" on the fault surface in deep.