Evaluating Static and Dynamic Stress Transfer Triggering

评估静态和动态应力转移触发

• 批准号: 0003505
• 负责人: Susanna Gross
• 金额: $ 10.5万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003505&HistoricalAwards=false
• 关键词: Evaluating; Static; Dynamic; Stress; Transfer

Abstract for proposal EAR0003505 (PH # 12x)Title: Evaluating Static and Dynamic Stress Transfer TriggeringPI's: S. Gross, University of ColoradoThe goal of this research is to study the triggering of earthquakes, especially aftershocks. The clear association of aftershocks with their mainshocks suggests that mainshocks trigger their aftershocks, but the mechanisms of that triggering are still debated. Triggering studies have repeatedly shown that aftershocks occur preferentially in fault zones upon which stresses have been concentrated as a result of permanent fault offset. This is surprising because these stress changes can be very small, orders of magnitude smaller than the stress change on an earthquake source. Recent results reveal that the much larger transient stress changes, generated by passing seismic waves, are also a viable triggering model. In order to decide which models are best, I will apply similar statistical measures to each model and apply them to the same data to compare them as fairly as possible. With this aim, I will study both static and dynamic stress transferred in both the 1992 Landers and 1999 Hector Mine earthquake sequences. I will evaluate the correlation of stress changes with aftershock distributions, using a unified battery of statistical tests so that the most consistent models may be identified and the influence of model errors quantified. In addition to comparing static and dynamic triggering models, I will explore models that include stresses due to postseismic processes, and see if inversions for the background stress state are consistent between the two sequences.

提案EAR0003505（PH # 12x）摘要标题：评估静态和动态应力转移触发PI：S。格罗斯，科罗拉多大学这项研究的目标是研究地震的触发，特别是余震。余震与主震的明显关联表明主震触发了余震，但触发机制仍有争议。触发研究一再表明，余震优先发生在断层带上的应力已集中作为永久断层偏移的结果。这是令人惊讶的，因为这些应力变化可能非常小，比震源上的应力变化小几个数量级。最近的结果表明，更大的瞬态应力变化，通过地震波产生的，也是一个可行的触发模型。为了决定哪些模型是最好的，我将对每个模型应用类似的统计措施，并将它们应用于相同的数据，以尽可能公平地比较它们。有了这个目标，我将研究静态和动态应力转移在1992年兰德斯和1999年赫克托矿地震序列。我将使用一组统一的统计测试来评估应力变化与余震分布的相关性，以便识别最一致的模型并量化模型误差的影响。除了比较静态和动态触发模型，我将探讨模型，包括由于震后过程的应力，并看看是否为背景应力状态的反演是一致的两个序列之间。