Collaborative Research: NSFGEO-NERC: Magnetotelluric imaging and geodynamical/geochemical investigations of plume-ridge interaction in the Galapagos

岩浆是如何从地幔流到地表的，人们对此知之甚少。它是缓慢地流过地幔，还是快速地流过富含熔体的通道？研究这个问题将有助于了解海底火山在哪里形成，以及它们喷发的频率。该项目将在加拉帕戈斯群岛获得新的地球物理和地质数据。这一地区从主群岛一直到几百公里外的大洋中脊都有火山活动。研究人员将联合收割机将新数据与理论模型相结合，以测试岩浆流动的不同模型。这些结果对其他地区，如留尼汪岛、亚速尔群岛和复活节岛以及全球俯冲带都很重要。更广泛的影响包括支持和培训一名研究生和博士后学者，为早期职业科学家提供参加研究巡航的机会，与加拉帕戈斯的查尔斯达尔文基金会合作，以及向公众和K-12学生宣传。这是一个由国家科学基金会地球科学理事会（NSF/GEO）和联合王国国家环境研究理事会（NERC）通过NSF/GEO-NERC牵头机构协议联合资助的项目。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。一旦成功地共同确定了奖励建议，每个机构将资助各自国家机构科学家的预算比例。拟议的工作旨在通过综合多学科研究，大大提高对软流圈熔体输送和熔体局部化过程的理解。作为一个案例研究，该项目将侧重于加拉帕戈斯地幔柱/洋中脊的相互作用，这一现象以神秘的沃尔夫-达尔文线性构造为例。建议的工作包括三个关键组成部分：（1）新的海洋电阻率成像使用大地电磁数据集成像熔体分布（部署90个海底宽带大地电磁测点）; ⑵地球化学分析沿着加拉帕戈斯北方线性构造和加拉帕戈斯西部扩张中心现有和新采的样品的主要和微量元素、挥发物含量、Sr、Nd、Pb和Fe同位素;（3）两相熔体通道化的地球动力学模拟，以限制熔体局部化的物理可行性。这些结果将被整合，以产生一个新的全球模式的羽脊相互作用和软流圈熔体transmittinggenerally.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

How magma flows from the Earth’s mantle to the surface is poorly understood. Does it flow slowly through the mantle, or quickly through melt-rich channels? Answering this question will help understand where seafloor volcanoes form and how frequently they erupt. The project will acquire new geophysical and geological data in the Galapagos islands. This region has volcanism all the way from the main archipelago to the mid-ocean ridge a few hundred km away. The investigators will combine the new data with theoretical modeling to test different models for magma flow. The results will be important for other locations such as Reunion Island, Azores Islands, and Easter Island as well as global subduction zones. Broader impacts include support and training of a graduate student and postdoctoral scholar, opportunities for early career scientists to participate in the research cruise, collaboration with the Charles Darwin Foundation in Galapagos, and outreach to the public and K-12 students. 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.The proposed works aims to significantly improve the understanding of melt transport in the asthenosphere, and melt localization processes, through an integrated multidisciplinary study. As a case study, the project will focus upon mantle plume/mid-ocean ridge interaction in the Galapagos which is exemplified by the enigmatic Wolf-Darwin Lineament. The proposed work includes three key components: (1) New marine resistivity imaging using magnetotelluric data sets for imaging melt distribution (with deployment of 90 ocean bottom broadband MT sites); (2) Geochemical analysis (major and trace elements, volatile content, Sr, Nd, Pb and Fe isotopes) of existing and new dredge samples along the northern Galapagos lineaments and Western Galapagos Spreading Center; and (3) Geodynamical modeling of two-phase melt channelization to constrain the physical viability of melt localization. These results will be integrated to generate a new global model for plume-ridge interaction and asthenospheric melt transport in general.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.