NERC-NSFGEO: Imaging the magma storage region and hydrothermal system of an active arc volcano

这个项目将收集兄弟火山的电磁数据，兄弟火山是世界上研究得最好的海底火山。这些数据将绘制活火山内部活动的图像，并绘制流体流动路径。流体的流动导致矿物质的沉淀，从而形成重金属沉积物。新的和现有的数据将被综合起来估计在这座火山沉积的重金属的数量。更广泛的影响包括通过邮轮研究博客吸引公众；对研究人员进行电磁方法和地球物理解释方面的培训；在课堂、会议和利益相关者面前展示成果；通过与来自美国、英国、新西兰、德国、意大利和瑞士的同事合作，建立国际伙伴关系。这是一个由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助的项目。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。在成功地共同确定一个奖项推荐后，每个机构资助预算的比例，以支持各自国家机构的科学家。热液循环是固体地球与海洋化学交换和热交换的关键机制，在火山灾害中起着重要作用。海洋钻探提供了对海底热液系统上层几百米的重要见解，但更深的流体路径及其与下垫岩浆热源的关系却知之甚少。部分熔体、热液流体和伴生矿床都具有独特的电阻率。该项目将进行独特的电磁实验，首次对活火山兄弟火山的热液系统内部工作和岩浆储存区进行三维成像。兄弟火山是汤加-克马德克弧的一部分，是全球研究得最好的海底弧火山。在本次实验中，将使用兄弟火山的两个三维有源电磁数据网格来约束热液流体的流动路径和岩浆管道系统的结构。成像将达到陆地弧状火山无法达到的分辨率，并将达到钻探无法达到的深度。该数据集生成的三维电阻率模型将与地震、磁、热流和取心数据相结合，以提高地下结构分辨率，并更准确地应用经验关系来估计岩浆-热液系统的孔隙度、渗透率、硫化物矿化和熔体分数。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will collect electromagnetic data at Brothers volcano, the best-studied submarine volcano in the world. These data will image the inner workings of an active volcano and map fluid flow paths. Fluid flow leads to the precipitation of minerals that form heavy metal deposits. New and existing data will be integrated to estimate the amount of heavy metals deposited at this volcano. Broader impacts include engaging the public through a research cruise blog; training a researcher in electromagnetic methods and geophysical interpretation; presenting results in classrooms, at conferences, and to stakeholders; and building international partnerships through collaboration with colleagues from the US, UK, New Zealand, Germany, Italy, and Switzerland. This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.Hydrothermal fluid circulation is the key mechanism of chemical and thermal exchange between the solid Earth and oceans and plays an important role in volcanic hazard. Ocean drilling has provided important insights into the upper few hundred meters of submarine hydrothermal systems, but deeper fluid pathways and their relationship with the underlying magmatic heat source are poorly known. Partial melts, hydrothermal fluids and associated mineral deposits all have distinctive electrical resistivity. This project will conduct a unique electromagnetic experiment to image for the first time in three dimensions the inner workings of the hydrothermal system and underlying magma storage region of Brothers volcano, an active arc volcano. Brothers volcano is part of the Tonga-Kermadec arc and is the best-studied submarine arc volcano globally. During this experiment, two 3D grids of active-source electromagnetic data collected at Brothers volcano will be used to constrain the hydrothermal fluid flow paths and architecture of the magma plumbing system. The imaging will achieve a resolution that is impossible at terrestrial arc volcanoes and will reach depths beyond those accessible by drilling. The 3D resistivity models generated from this dataset will be integrated with seismic, magnetic, heat flow, and coring data to improve structural resolution of the subsurface and to more accurately apply empirical relationships to estimate porosity, permeability, sulfide mineralization, and melt fraction of the magma-hydrothermal systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.