Collaborative Research: SERPENT: Serpentinite, Extension and Regional Porosity Experiment across the Nicaraguan Trench

合作研究：SERPENT：尼加拉瓜海沟的蛇纹岩、延伸和区域孔隙度实验

• 批准号: 0841114
• 负责人: Steven Constable
• 金额: $ 70万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 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: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0841114&HistoricalAwards=false
• 关键词: Collaborative; Research; SERPENT; Serpentinite; Extension

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The thin, rocky shell of the Earth, the lithosphere, is broken into a mosaic of thin plates that are inconstant motion. Along some boundaries between plates, one slides beneath the other and is consumed in a process known as subduction. Most of great earthquakes and violent volcanic eruptions occur at subduction zones. Both of these processes are significantly affected by the amount of water that is carried into the interior with the downgoing plate, but these processes remain poorly understood because the amount of water entering the subduction system remains poorly constrained. A major carrier of water is the mineral serpentine, and one of the major uncertainties is the volume of water that is being carried into the subduction system by serpentinized upper mantle. Electromagnetic geophysical methods are sensitive to the presence and concentration of water at depth in the Earth. This project consists of a large-scale electromagnetic experiment along a 300 km profile off Nicaragua in a region that shows evidence for substantial fault related fluid circulation in the crust and possibly in the upper mantle, and high Ba/La ratios and water contents in adjacent onshore volcanics suggesting a strong slab fluid input into the arc-melting. This survey will combine controlled-source electromagnetics (CSEM) with broadband and long period magnetotellurics (MT) to provide a comprehensive picture of the conductivity structure from the seafloor to the upper mantle, representing the entire input into this part of the Central American subduction zone. In addition to the societal relevance of improving our understanding of processes that produce earthquakes and volcanic eruptions, this project will promote international scientific cooperation and support two Ph.D. students.

该奖项根据 2009 年美国复苏和再投资法案（公法 111-5）提供资金。地球的薄岩石壳（即岩石圈）被分解成不断运动的薄板马赛克。沿着板块之间的某些边界，一个板块在另一个板块下方滑动，并在称为俯冲的过程中被消耗。大多数大地震和剧烈火山喷发都发生在俯冲带。这两个过程都受到下降板块带入内部的水量的显着影响，但由于进入俯冲系统的水量仍然很少受到限制，因此这些过程仍然知之甚少。水的主要载体是蛇纹石矿物，主要的不确定性之一是蛇纹石化上地幔带入俯冲系统的水量。电磁地球物理方法对地球深处水的存在和浓度敏感。该项目包括沿尼加拉瓜海岸线 300 公里剖面进行的大规模电磁实验，该实验显示了地壳和上地幔中存在大量与断层相关的流体循环的证据，以及邻近区域的高 Ba/La 比值和含水量。陆上火山表明有强烈的板片流体输入到电弧熔化中。 这项调查将把受控源电磁学 (CSEM) 与宽带和长周期大地电磁学 (MT) 结合起来，提供从海底到上地幔的传导结构的全面图像，代表中美洲俯冲带这一部分的全部输入。除了提高我们对地震和火山爆发过程的理解的社会意义外，该项目还将促进国际科学合作并支持两名博士生。学生。