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

合作研究：巴拿马盆地地热加热和哥斯达黎加裂谷的地壳演化

• 批准号: 1558797
• 负责人: Ryan Pollyea
• 金额: $ 22.54万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1558797&HistoricalAwards=false
• 关键词: Collaborative; Research; Geothermal; heating; Panama

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.

海洋壳和深海之间的热量和传质对地球的冷却，关键的生物地球化学物种的运动以及海洋底部生物群落的维持具有全球影响。此外，最近的研究表明，地热加热是深海循环的重要驱动力，这是海洋 - 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模型，即地壳热和传质如何影响深海循环。拟议的工作将使人们更好地了解深海循环及其与全球大气系统的联系。拟议的工作还将在理解地壳热和传质时如何随着海洋壳年龄的年龄的发展而产生重要的进步。 该项目支持培训研究生和本科生。拟议的研究构成了由英格兰达勒姆大学领导的大型多学科，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学，地球物理和导电热流数据，以及来自赤道太平洋中巴拿马盆地的现有数据集，以构建从哥斯达黎加（COSTA RIFT）轴（CRR）轴（CRR）轴到沉积物覆盖的600万年Crust的水热热和质量通量模型。 目标是：（1）了解水热热传递如何随着岩石圈年龄的形式发展； （2）开发高分辨率模型，以显示水热热和传质如何在区域尺度上影响深海循环。 为了实现这些目标，在1.3至5.3 mA之间的沉积物覆盖地壳中获得了85个新的导电热流量测量，并与多通道地震线共同划分。 这些数据将与现有的热流数据以及英国领导的项目的地球物理和海洋学数据一起使用，以在年轻的沉积物覆盖地壳中构建水热热传递的数学和数值模型。此外，关于轴向和近轴区域中熔体和部分熔体分布的其他地球物理数据，再加上水样的水样，用于氦分析和海洋学数据，表征了CRR的海底边界层和水热羽状结构，将约束在脊轴和近距离地区的水热循环模型。这些分析将提供CRR和近轴区域水热输出的首次估计，并将指导对水热活动，地球化学运输和CRR的生物群落的未来探索。最后，使用英国领导的项目收集的详细海洋数据套件，水热模型将作为海洋循环高分辨率模型的输入。