4D Imaging of Oceanic Transform Fault Material Properties Variations During the Earthquake Cycle

地震周期期间海洋转换断层物质特性变化的 4D 成像

• 批准号: 1232725
• 负责人: Robert van der Hilst
• 金额: $ 25万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1232725&HistoricalAwards=false
• 关键词: 4D; Imaging; Oceanic; Transform; Fault

Many large and damaging earthquakes occur in highly populated areas, such as Indonesia, Japan, Chile and California. For that reason, forecasting earthquakes, and predicting their effects is a long-sought goal of earthquake seismology. Achieving those goals requires improved understanding of the faults and fault processes that lead to large earthquakes. That understanding is impaired by the extreme complexity of most fault and fault systems. Though they do not occur in populated areas, oceanic transform faults are comparatively simple natural laboratories, where some fundamental processes have been observed. Transform faults on the East Pacific Rise (EPR) offer a unique opportunity to study how spatial and temporal variation of fault zone properties control earthquake rupture because the largest earthquakes on these faults occur at regular intervals, and related variations of the properties in the fault zone have been observed. This project has three objectives that will advance out understanding of fault mechanics. One is to determine which spatial variations of material properties control the occurrence of the largest earthquakes. The second is to understand how fault zone properties change with time over the earthquake cycle, and the third is to understand how variations of the material properties are related to earthquake seismicity.The broader impacts of this project include support for two young post doctoral researchers; the primary broader impact is that, while it is not directly focused on seismic hazard estimates, may be expected to lead to a better understanding of earthquake processes, with accordingly high potential societal benfits.

许多大的破坏性地震发生在人口稠密的地区，例如印度尼西亚、日本、智利和加利福尼亚。因此，预测地震及其影响是地震学长期追求的目标。实现这些目标需要更好地了解导致大地震的断层和断层过程。大多数断层和断层系统的极端复杂性削弱了这种理解。尽管海洋转换断层并不出现在人口稠密的地区，但它们是相对简单的自然实验室，已经观察到了一些基本过程。东太平洋海隆 (EPR) 上的转换断层为研究断层带特性的时空变化如何控制地震破裂提供了独特的机会，因为这些断层上最大的地震定期发生，以及断层带特性的相关变化已被观察到。该项目有三个目标，将促进对断层力学的理解。一是确定材料特性的哪些空间变化控制最大地震的发生。第二个是了解断层带特性如何在地震周期中随时间变化，第三个是了解材料特性的变化如何与地震活动相关。该项目的更广泛影响包括支持两名年轻的博士后研究人员；主要的更广泛的影响是，虽然它不直接关注地震灾害估计，但预计将有助于更好地了解地震过程，从而带来较高的潜在社会效益。