Collaborative Research: Linking stress changes and hydrothermal activity during a non-eruptive spreading event.

合作研究：将非喷发扩散事件期间的应力变化和热液活动联系起来。

• 批准号: 0937285
• 负责人: Emilie Hooft Toomey
• 金额: $ 17.76万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0937285&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; stress; changes

Mid ocean ridges are sites of creation of new ocean floor, a process that is characterized by high seismicity (earthquakes) and active volcanism, and vigorous hydrothermal circulation. The latter is evidenced by jets of super heated water rising from vents in the sea floor (the now-famous black smokers) that support exotic biological communities. An important scientific goal is understanding the dynamics of these systems. Earthquakes occur within the upper brittle crust in response to stresses and their distribution in space and time is a primary source of information about dynamic subsurface geologic processes. These earthquakes are associated with both the tectonic and magmatic events that account for plate spreading and they create fractures that influence the patterns of hydrothermal circulation, heat extraction and water-rock reactions. As such, long duration studies of micro-earthquakes are key to multidisciplinary studies of the dynamic processes are mid-ocean ridges. The objectives of this project are to infer spatial and temporal patterns of stress changes associated with the earthquake swarms in late January and February 2005, to understand the impact of the associated regional spreading event on the characteristics of hydrothermal systems and magmatic segmentation, and to determine how stress changes associated with the regional spreading event affect seismic anisotropy and tidal triggering.

洋中脊是新洋底形成的地点，这一过程的特点是地震活动频繁、火山活动活跃和热液循环活跃。后者的证据是从海底喷口（现在著名的黑烟囱）升起的超热水喷射，支持外来生物群落。一个重要的科学目标是了解这些系统的动力学。地震发生在脆性地壳上部，是对应力的响应，地震在空间和时间上的分布是关于地下动态地质过程的主要信息来源。这些地震与解释板块扩张的构造和岩浆事件有关，它们产生的裂缝影响热液循环、热量提取和水岩反应的模式。因此，持续时间长的微地震研究是大洋中脊动力过程多学科研究的关键。该项目的目标是推断与2005年1月下旬和2月震群相关的应力变化的空间和时间模式，了解相关区域扩张事件对热液系统和岩浆分段特征的影响，并确定与区域扩张事件相关的应力变化如何影响地震各向异性和潮汐触发。