Collaborative Research: Geothermal heating of the Panama Basin and crustal evolution of the Costa Rica Rift

洋壳和深海之间的热量和质量转移对地球的冷却、关键生物地球化学物种的移动和海底生物群落的维持具有全球性的影响。此外，最近的研究表明，地热加热是深海环流的重要驱动力，深海环流是海洋-大气系统的主要组成部分。作为大型多学科和国际研究计划的一部分，该项目将开发第一个高分辨率的地壳热量和质量转移如何影响深海环流的模型。拟议的工作将有助于更好地了解深海环流及其与全球海洋-大气系统的联系。这项拟议的工作还将在理解地壳热量和质量转移如何随着洋壳年龄的变化方面取得重要进展。该项目支持研究生和本科生的培养。这项拟议的研究是由英国达勒姆大学牵头的大型多学科、多机构项目的组成部分。这项研究将使用最近收集的物理海洋、地球物理和传导热流数据，以及来自赤道太平洋巴拿马盆地的现有数据集，构建从哥斯达黎加裂谷(CRR)轴到沉积覆盖的600万年前地壳的热液热流和质量通量模型。目标是：(1)了解随着岩石圈年龄的变化，热液热传递如何随地壳结构而演变；(2)开发高分辨率模型，说明热液热和质量传递如何在区域范围内影响深海环流。为了实现这些目标，在与多道地震线共处的1.3~5.3 Ma的沉积地壳中，获得了85个新的传导热流测量结果。这些数据将与现有的热流数据以及英国牵头的项目的地球物理和海洋数据一起使用，以建立年轻沉积物覆盖的地壳中水热传递的数学和数值模型。此外，关于轴向和近轴区域熔体和部分熔体分布的其他地球物理数据，加上用于氦分析的水样和描述CRR海底边界层和热液羽流结构的海洋学数据，将制约脊轴和近轴区域的热液循环模型。这些分析将提供对CRR和近轴地区水热输出的第一次估计，并将指导未来对CRR的热液活动、地球化学运输和生物群落的探索。最后，热液模型将作为高分辨率海洋环流模型的输入，使用在英国牵头的项目期间收集的一套详细的海洋数据。

Heat and mass transfer between the oceanic crust and the deep ocean has global implications for the cooling of the earth, the movement of critical biogeochemical species, and the maintenance of ocean bottom biological communities. Moreover, recent studies show that geothermal heating is an important driver of deep ocean circulation, which is a major component of the ocean-atmosphere system. As a part of a large multidisciplinary and international research program, this project will develop the first high-resolution models of how crustal heat and mass transfer impact deep ocean circulation. The proposed work will lead to a better understanding of deep ocean circulation and its connection with the global ocean-atmosphere system. The proposed work also will yield an important advance in understanding how crustal heat and mass transfer evolves as the oceanic crust ages. The project supports the training of graduate and undergraduate students. The proposed research forms an integral component of the large multi-disciplinary, multi-institutional project led by the University of Durham, England. This research will use recently collected physical oceanographic, geophysical, and conductive heat flow data, together with existing data sets from the Panama Basin in the equatorial Pacific Ocean, to construct hydrothermal heat and mass flux models from the Costa Rica Rift (CRR) axis to sediment-covered, 6 million year old crust. The goals are: (1) to understand how hydrothermal heat transfer evolves with crustal structure as the lithospheric ages; and (2) to develop high resolution models that show how hydrothermal heat and mass transfer impacts deep ocean circulation on a regional scale. To achieve these goals, 85 new conductive heat flow measurements have been obtained in sediment-covered crust at ages between 1.3 and 5.3 Ma co-located with a multi-channel seismic line. These data will be used together with existing heat flow data, and the geophysical and oceanographic data from the British-led project, to construct mathematical and numerical models of hydrothermal heat transfer in young sediment-covered crust. In addition, other geophysical data on the distribution of melt and partial melt in axial and near-axial regions, coupled with water samples for helium analysis and oceanographic data characterizing the ocean bottom boundary layer and hydrothermal plume structure at the CRR, will constrain models of hydrothermal circulation at the ridge axis and in near-axial regions. These analyses will provide the first estimates of hydrothermal heat output at the CRR and near-axis region, and will guide future exploration of hydrothermal activity, geochemical transport, and the biological communities at the CRR. Finally, the hydrothermal models will serve as input to high-resolution models of ocean circulation using the detailed suite of oceanographic data collected during the British-led project.