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

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。地球的薄岩石壳，岩石圈，被打破成一个不断运动的薄板马赛克。沿着板块之间的某些边界，一个板块滑到另一个板块之下，并在一个被称为俯冲的过程中被消耗掉。大多数大地震和剧烈的火山爆发都发生在俯冲带。这两个过程都受到随下行板块进入内部的水量的显著影响，但这些过程仍然知之甚少，因为进入俯冲系统的水量仍然受到很大的限制。水的一个主要载体是矿物蛇纹石，主要的不确定性之一是被蛇纹石化的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很敏感。该项目包括一个大规模的电磁实验沿着一个300公里的剖面尼加拉瓜在一个区域，显示大量的断层有关的流体循环在地壳中，可能在上地幔，高Ba/La比和水含量在邻近的陆上火山表明一个强大的板流体输入到电弧熔融。 这项调查将把联合收割机可控源电磁学与宽带和长周期大地电磁学结合起来，全面描绘从海底到上地幔的传导性结构，反映中美洲俯冲带这一部分的全部输入。除了提高我们对产生地震和火山爆发的过程的理解的社会意义外，该项目还将促进国际科学合作，并支持两个博士学位。学生

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.