Studies of Global and Regional Seismicity

全球和区域地震活动研究

• 批准号: 0510007
• 负责人: Goran Ekstrom
• 金额: $ 38.2万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2006-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510007&HistoricalAwards=false
• 关键词: Studies; Global; Regional; Seismicity

This project involves studies of global and regional seismicity.Central to the project is a continuation of the HarvardCentroid-Moment-Tensor (CMT) Project, which now represents a22-year-long effort to analyze global earthquake activity and tomaintain a comprehensive and authoritative catalog of earthquakefocal mechanisms, the CMT Catalog. In addition to the systematicanalysis and of earthquakes and dissemination of earthquake information,the research also includes the development of a dynamic earthquakemoment-tensor database. The new catalog will be searchable on theweb, and will include auxiliary data, such as information about theseismograms and Earth model used in the analysis, the quality ofthe solution, and any history of updates to the results.A second component of the project is an examination of previouslyundetected earthquakes. More than 1,800 events with magnitudes greaterthan 4.7 have recently been found using a new detection algorithm, anda substantial subset of these are clearly not common earthquakes.The effort will involve a first-order, systematic analysisof the new events to determine why they eluded earlierdetection (e.g., whether all of the events lack high-frequencyradiation and are thus slow earthquakes) and the specific tectonic(or non-tectonic) explanations for several specific groups ofdetections, including (1) events associated with volcanic eruptionsor collapses; (2) events associated with glaciers in Alaska, Antarctica,and Greenland; and (3) events off the coast of North Carolina,possibly associated with submarine slumping.

这个项目涉及全球和区域地震活动的研究。该项目的核心是哈佛质心-矩-张量（CMT）项目的延续，该项目代表了长达22年的努力，旨在分析全球地震活动，并维护一个全面而权威的地震震源机制目录，即CMT目录。除了系统的地震分析和地震信息的传播外，研究还包括地震动态张量数据库的开发。新的目录将可在网上搜索，并将包括辅助数据，如在分析中使用的地震图和地球模型的信息，解决方案的质量，以及结果更新的任何历史记录。该项目的第二个组成部分是对以前未探测到的地震进行检查。最近使用一种新的检测算法发现了1800多个震级大于4.7的地震，其中很大一部分显然不是常见的地震。这项工作将包括对新事件的一阶系统分析，以确定它们为什么没有被早期探测到（例如，是否所有事件都缺乏高频辐射，因此是缓慢的地震），以及对几组特定探测的特定构造（或非构造）解释，包括(1)与火山爆发或崩塌有关的事件；(2)与阿拉斯加、南极洲和格陵兰冰川有关的事件；(3)北卡罗莱纳海岸附近的事件，可能与潜艇沉没有关。