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

震源机制、断层滑移和应变率对地震群聚的影响

• 批准号: 1045876
• 负责人: David Jackson
• 金额: $ 22.04万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-15 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1045876&HistoricalAwards=false
• 关键词: Effects; Focal; Mechanisms; Fault; Slip

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.

描述地震、断层和构造应变之间关系的模型通常分为三种不同类型：（a）基于地震活动性的模型，（B）基于断层的模型，（c）基于大地测量或地质学观测到的应变率的模型。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。基于应变的模型假设地震率与某种形式的应变率有关。他们通常假设地震可以发生在任何地方，尽管基于应变的模型可以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，但没有包括断层性质，断层历史，已知断层上的大小地震的应力，地震触发和构造应变积累。在本项目中，研究人员将构建包含上述所有影响的地震相互作用的短期和长期模型。他们的时间聚集模型将基于余震延迟时间的大森定律，并根据观测到的大地震早期余震检测能力的丧失进行修改。他们的模型将有几个可调整的参数，这些参数将根据可能性标准进行优化，以最好地拟合地震数据。然后，他们将模型形式化为预测，在地震可预测性研究合作实验室（CSEP）计划中进行测试。