Quantifying heat and chemical fluxes between the oceans and ocean crust

在大多数地质时期，一个重要的全球地球化学循环涉及洋壳的产生、改造和再循环。这个循环将地幔成分带入地壳和海洋，并通过俯冲带将海水成分带入地幔。作为地球上最大的含水层，海洋的全部体积以100到1000 KYR的时间尺度在洋壳中循环。这种海水产生的流体流经地壳含水层，吸收了约30%的岩石圈热量，促进了洋壳和海洋之间的化学交换，从而缓和了海水化学和地下生物圈。 我的研究计划有两个相互关联的主题。首先，我们将研究与海脊侧向环境(例如，洋壳所在地区)中流体流动和低温交换有关的全球尺度的地球化学循环。我们将使用双管齐下的方法，建立水文地质模型，探索海水如何流经大洋结壳，以及如何在大洋结壳和海洋之间流动，以及现场和地球化学研究，以量化不同类型的流体流动如何改变结壳的化学成分。我们还将研究海洋和洋壳化学的长期变化，重点是洋壳中二氧化碳的自然封存。其次，我们将在从10 KYR到小时的一系列时间尺度上研究与大洋中脊的高温热液系统有关的化学和热通量。我们将使用遥控潜水器、载人潜水器和一艘国际钻井船回收的样本，以及从一个新的海洋观测网络传来的数据。

A significant global geochemical cycle throughout most of geological time involves the creation, alteration, and recycling of the oceanic crust. This cycle brings mantle components into the crust and oceans, and seawater components into the mantle through subduction zones. As the largest aquifer on earth, the entire volume of the ocean is cycled through the ocean crust on timescales of 100 to 1000 kyr. This flow of seawater-derived fluids through the crustal aquifer extracts ~30% of the lithospheric heat and promotes chemical exchange between the ocean crust and oceans that moderates seawater chemistry and the subsurface biosphere. My research program has two interrelated themes. First, we will investigate global-scale geochemical cycles related to fluid flow and low temperature exchange in the ridge flank environment (e.g., where ocean crust is > 1 Myr). We will use a two pronged approach, hydrogeological modeling to explore how seawater flows through the ocean crust, and between the ocean crust and the oceans, and field and geochemical studies to quantify how the chemistry of the crust is modified by different styles of fluid flow. We will also investigate secular changes in the chemistry of the oceans and ocean crust, with a focus on the natural sequestration of CO2 in the ocean crust. Second, we will examine the chemical and heat fluxes associated with high temperature, hydrothermal systems at mid-ocean ridges on a range of timescales, ranging from 10 kyr to hours. We will use samples recovered by remotely operated vehicles, manned submersible and an international drillship, and data streaming in from a novel ocean observing network.