Elastodynamic Event Sequences on Rough Faults

断层的几何和物质不均匀性长期以来一直被认为是影响地震行为的重要特征。 最近，应力不均匀性的作用已经开始被认为是一个潜在的中心特征，特别是随着应力不均匀性本身已经可以在均匀平面断层上产生一组非常丰富和复杂的类似地震的行为的证明。 缺少的是理解两种类型的异质性，静态几何和材料异质性，以及动态应力异质性，如何结合和相互作用，以产生更真实的行为。这项研究旨在进一步发展一条线的建模扩展弹性动力学模拟非平面几何形状。 具体地说，其目的是发展粗糙断层几何形状的模拟。通过研究断层上的长事件序列，动力学吸引子的发展，从而可以检查应力不均匀性与任何几何不均匀性的相互作用。 除了开发技术，我们还将模型应用于一系列观测，包括正常应力效应、破裂开始和终止以及余震。这些应用与更好地理解摩擦、改进基于分段的长期危险估计和基于余震的短期危险估计有关。

Geometrical and material heterogeneities in faults have long been viewed as a crucial feature affecting earthquake behavior. More recently, the role ofstress heterogeneities has begun to be recognized as a potentially central feature,particularly with the demonstration that stress heterogeneities alone already can produce a remarkably rich and complex set of earthquake-likebehaviors on uniform planar faults. What is missing is an understanding of howthe two types of heterogeneities, the static geometrical and materialheterogeneities, and the dynamic stress heterogeneities, might combineand interact to produce even more realistic behavior.This research seeks to further develop a line of modeling which extends elastodynamic simulations to nonplanar geometries. Specifically, the aim is to develop simulations of rough fault geometries.By studying long sequences of events on the faults, the dynamical attractordevelops, and thus the interaction of stress heterogeneities with anygeometrical heterogeneities can be examined. As well as developing the technology, we are applying the modelto a set of observations, including normal stress effects, ruptureinitiation and termination, and aftershocks. These applicationshave relevance to understanding friction better, improving long term hazard estimation based on segmentation, and short term hazard estimationbased on aftershocks.