Effects of Focal Mechanisms, Fault Slip, and Strain Rate on Earthquake Clustering

描述地震、断层和构造应变之间关系的模型通常有三种不同的类型：基于(a)地震活动性的模型，(b)断层模型，以及(c)大地测量或地质观测到的应变率模型。基于地震的模型通常只依赖于过去的地震数据，完全忽略了断层信息。基于断层的模型通常只适用于预先确定的断层上的地震，无论是单独的还是组合的。基于应变的模型假定地震率与某种形式的应变率有关。他们通常假设地震可能发生在任何地方，尽管基于应变的模型可能使用断层滑动信息来推断应变率。虽然存在混合模型，但它们通常假设未来的大地震将发生在预先确定的断层上。许多现有的模型显示出适度的技巧，但没有一个包括断层特性、断层历史、已知断层上和附近的大地震和小地震的应力、地震触发和构造应变积累。在这个项目中，研究人员将构建包括上述所有影响的地震相互作用的短期和长期模型。他们的时间聚类模型将以余震延迟时间的Omori定律为基础，并对其进行修改，以考虑到观测到的对大地震早期余震的探测能力的丧失。他们的模型将有几个可调整的参数，这些参数将根据似然准则进行优化，以最适合地震数据。然后，他们将把这个模型形式化，作为一个预报，在地震可预测性研究合作实验室（CSEP）项目中进行测试。

Models to describe the relationship between earthquakes, faults, and tectonic strain generally three different types: those based on (a) seismicity,(b) faults, and (c) geodetically or geologically observed strain rates. Seismicity-based models often rely only on past earthquake data, ignoring fault information completely. Fault-based models generally apply only to earthquakes on pre-identified faults, either singly or in combination. Strain-based models assume that earthquake rates are related to some form of strain rate. They generally assume that earthquakes can occur anywhere, although strain based models may use fault slip information to infer strain rates. While hybrid models exist, they generally assume that future large earthquakes will occur on pre-identified faults. Many existing models show modest skill, but none includes fault properties, fault history, stresses from large and small earthquakes on and off of known faults, earthquake triggering, and tectonic strain accumulation. In this project the researchers will construct short-term and long-term models of earthquake interactions including all of the above effects.Their models of temporal clustering would be based on the Omori law of aftershock delay times, modified to account for the observed loss of detection capability for early aftershocks of large earthquakes. Their models would have several adjustable parameters, which would be optimized for best fit to earthquake data according to a likelihood criterion. They would then formalize the model as a forecast to be tested in the Collaboratory for the Study of Earthquake Predictability (CSEP) program.