标题： FASTDASH：基于边界元法并利用H矩阵加速的复杂断层系统三维地震循环模拟实现 显示英文标题

标题： FASTDASH: An Implementation of 3D Earthquake Cycle Simulation on Complex Fault Systems Using the Boundary Element Method Accelerated by H-matrices

摘要： 断层系统在自然界中具有几何上复杂的结构，例如台阶状过渡、弯曲、分支和粗糙度。许多地质学和地球物理学研究表明，自然界中断层系统的几何复杂性对地震和非地震事件的触发、停止和复发起着决定性作用。然而，由于算法限制，大多数滑动动力学模型是在平面断层上进行的。我们开发了一种三维准动态滑动动力学模型以克服这一限制。由于滑动引起的弹性响应在边界元方法中计算为矩阵-向量乘法，通过使用分层矩阵可以加速该计算。计算复杂度从O(N^2)降低到O(N log N)，其中N是自由度的数量。我们将代码与静态裂纹解析解以及南加州地震中心的SEAS基准/验证练习进行了验证。此外，我们进一步将此方法应用于2023年卡赫拉曼马拉什-土耳其双震序列中重新活动的具有复杂几何形状的实际断层系统，生成的滑动序列与实际观测结果高度吻合。 显示英文摘要

摘要： Fault systems have geometrically complex structures in nature, such as stepovers, bends, branches, and roughness. Many geological and geophysical studies have shown that the geometrical complexity of fault systems in nature decisively influences the initiation, arrest, and recurrence of seismic and aseismic events. However, a vast majority of models of slip dynamics are conducted on planar faults due to algorithmic limitations. We develop a 3D quasi-dynamic slip dynamics model to overcome this restriction. The calculation of the elastic response due to slip is a matrix-vector multiplication in boundary element method, which can be accelerated by using hierarchical matrices. The computational complexity is reduced from the order of O(N^2) to O(N log N), where N is the number of degree of freedoms used. We validate our code with a static crack analytical solution and the SEAS benchmark/validation exercise from Southern California Earthquake Center. We further employ this method on a realistic fault system with complex geometry that was reactivated during the 2023 Kahramanmaras - Turkiye doublet earthquakes, generating slip sequences that closely match real observations.