EAR-PF: Exploring the evolution of faults and friction through dense repeater event catalogs

EAR-PF：通过密集的中继器事件目录探索故障和摩擦的演变

• 批准号: 1452375
• 负责人: William Frank
• 金额: $ 2.59万
• 依托单位: Frank, William B
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-11-01 至 2017-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1452375&HistoricalAwards=false
• 关键词: EAR; PF; Exploring; evolution; faults

Dr. William Frank has been granted an NSF Earth Sciences Postdoctoral Fellowship at the Massachusetts Institute of Technology (MIT) to investigate the ever-changing conditions at seismic faults using rapidly repeating earthquakes as in in situ probe. The evolving activity rates of rapidly repeating seismic events that can emit tens of events in several minutes provide a unique and direct window to seismically active faults and can shed light on what properties, such as temperature, pressure, or fluid pressure, control how friction evolves through time. Thanks to recent advances in the systematic search for repeating earthquakes, Dr. Frank will extend novel detection algorithms to different geological contexts. After detecting millions of events and consolidating them into regional catalogs, comparisons between different seismic contexts will help to better understand the common mechanisms of repeating earthquakes and what controls how a fault ruptures. In addition to detection techniques, there have been a number of new methodologies that will benefit from dense catalogs of collocated events and will help better constrain repeating earthquake mechanics. Taking advantage of the unique Undergraduate Research Opportunity Program at MIT, Dr. Frank will also mentor an undergraduate student who will develop the skills to make use of the high performance computing architectures necessary for modern seismology and adapt the developed detection algorithms to a dataset as his/her own personal project.The matched-filter search is a powerful tool to detect the multiplets, or family of events, of a single source using a previously identified event as a template. A systematic detection of template events to use as matched-filters is, however, necessary to obtain a wide and dense coverage of repeating sources. Both volcanoes and industrial injection/production sites are known to generate a significant amount of seismicity, but identified events have yet to be regrouped into families of repeating multiplets in many regions around the world. Such seismically active environments will be investigated through dense event catalogs generated by a continuous and systematic search first for templates and then for multiplets. In addition to the systematic cataloging of repeating seismicity in different geological contexts, Dr. Frank will also attempt to better constrain the spectral characteristics of repeating earthquakes as we still do not fully understand what makes repeating earthquakes reactivate at such rapid rates and how they differ from more typical earthquakes. Using recent spectral estimation methods to take advantage of the collocated nature of multiplets, he will separate the spectral contributions of the source, the path, and the site from the recorded seismograms to better constrain the properties of repeating earthquake sources.

威廉·弗兰克博士已获得美国国家科学基金会地球科学博士后奖学金在马萨诸塞州理工学院（麻省理工学院）调查不断变化的条件，在地震断层使用快速重复地震作为原位探测。 快速重复的地震事件可以在几分钟内发出数十个事件，其不断变化的活动速率为地震活动断层提供了一个独特而直接的窗口，并可以揭示温度，压力或流体压力等属性如何控制摩擦力随时间的演变。 由于最近在系统搜索重复地震方面取得的进展，弗兰克博士将把新的检测算法扩展到不同的地质背景。 在检测到数百万次地震事件并将其整合到区域目录中之后，不同地震背景之间的比较将有助于更好地理解重复地震的常见机制以及控制断层破裂的因素。 除了检测技术，还有一些新的方法，将受益于密集的目录同位事件，并将有助于更好地约束重复地震力学。 利用麻省理工学院独特的本科生研究机会计划，Frank博士还将指导一名本科生，培养他们利用现代地震学所需的高性能计算架构的技能，并将开发的检测算法应用于数据集，作为他/她自己的个人项目。匹配滤波器搜索是检测多重波或事件族的强大工具，使用先前识别的事件作为模板的单个源。 一个系统的检测模板事件使用匹配过滤器，但是，有必要获得广泛和密集的重复源的覆盖范围。 已知火山和工业注入/生产地点都会产生大量的地震活动，但在世界各地的许多地区，已确定的事件尚未被重新组合成重复的多重地震。 这样的地震活动环境将通过密集的事件目录进行调查，通过连续和系统的搜索，首先为模板，然后为多胞胎。除了对不同地质背景下的重复地震活动进行系统编目外，弗兰克博士还将试图更好地限制重复地震的频谱特征，因为我们仍然不完全了解是什么使重复地震以如此快的速度重新激活，以及它们与更典型的地震有何不同。 使用最近的频谱估计方法，以利用同位性质的多重，他将分离的频谱贡献的源，路径，和网站从记录的地震图，以更好地约束重复地震源的属性。