Collaborative Research: Heat Source and Flux Distributions in the Western Ross Sea Seafloor

合作研究：西罗斯海海底的热源和通量分布

• 批准号: 2217127
• 负责人: Masako Tominaga
• 金额: $ 89.58万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2217127&HistoricalAwards=false
• 关键词: Collaborative; Research; Heat; Source; Flux

Understanding the origins and nature of heat available at the base of the cryosphere is essential in deciphering the extent and residence time of the ice in Antarctica and its oceans. Constraints on parameters that control ice-sheet stability, response of the crust to ice loading and unloading, and the effects of volcanism and heat from Earth’s interior on overlying ice is of broad interest to the global climate change community. The goal of this study is to identify and to document the distribution of heat source and heat flux within the seafloor of the southwestern Ross Sea. Geothermal heat flux is one of the basic parameters that shape and control ice flow, ocean circulation, and ecosystem, connecting with subglacial hydrology and its influence on the ability of the ice sheet to slide and internally deform. Despite the importance, particularly in the Antarctic environments, there have been few investigations made in the Ross Sea on how lithospheric heat flux contributes to cryospheric dynamics over time. The project study site in the western Ross Sea seafloor comprises the Terror Rift, which represents the youngest phase of extension within the West Antarctic Rift System, one of the world’s largest rifts and the only one covered by continental ice sheets. The thinned western Ross Sea lithosphere and Terror Rift encompasses active volcanism that range from 5 million years to present-day, suggesting that Pliocene-Quaternary fault movement and dynamic changes in ice sheet extent and thickness over this period are concurrent with magmatic activities.This project will conduct a shipboard survey of the western Ross Sea seafloor. The datasets to be collected include seafloor heatflow/conductivity measurements, real-time seafloor visualization, water-column hydrothermal signal acquisition, and rock sampling via dredging. Heat flow and direct seafloor observations will provide an unprecedented context for seafloor-ocean interactions, addressing some of the biogeochemical cycles in the water column (e.g., chemical and nutrients contributions to the water column from seafloor volcanism and resultant hydrothermal systems) in constraining Ross Sea ecosystems. The compilation of all the data will enable the testing of hypotheses that magmatic intrusion and volcanism in the western Ross Sea is the primary lithospheric heat source that has influenced the dynamics of the ocean-cryosphere system in this region. Data collected will also allow us to refine current timeseries and geodynamics that drive one of the world’s major continental rift systems. Deliverables from this project will be new geospatial information data, including all the underway geophysics grids of the area, publicly available via NSF funded data repositories. After acquiring geochemistry and geochronology, the remaining rock samples will be archived at the Polar Rock Repository. The project will also train 1 postdoc, 2 graduate students, and at least 3 undergraduate students.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.

了解冰冻圈底部可用热量的来源和性质对于破译南极洲及其海洋冰的范围和停留时间至关重要。卸载，以及火山活动和地球内部热量对上覆冰的影响引起了全球气候变化界的广泛兴趣。这项研究的目的是确定并记录热源和热通量在地球内部的分布。罗斯海西南部海底地热热通量是塑造和控制冰流、海洋环流和生态系统的基本参数之一，与冰下水文及其对冰盖滑动和内部变形能力的影响有关。特别是在南极环境中，罗斯海很少有关于岩石圈热通量如何随时间影响冰冻圈动力学的研究。该项目研究地点位于罗斯海西部海底，包括恐怖裂谷。这是西南极裂谷系统中最年轻的扩张阶段，该系统是世界上最大的裂谷之一，也是唯一一个被大陆冰盖覆盖的裂谷。 变薄的西罗斯海岩石圈和恐怖裂谷包含了从 500 万年至今的活跃火山活动。 ，表明上新世-第四纪断层运动以及这一时期冰盖范围和厚度的动态变化与磁活动同时发生。该项目将对罗斯海西部海底进行船上调查。要收集的数据集包括海底热流/电导率测量、实时海底可视化、水柱热液信号采集以及通过疏浚进行的岩石采样和直接海底观测将为海底与海洋相互作用提供前所未有的背景，解决一些问题。限制罗斯海生态系统的水柱中的生物地球化学循环（例如，海底火山活动和由此产生的热液系统对水柱的化学和营养物贡献）所有的汇编。这些数据将能够检验罗斯海西部的磁侵入和火山活动是影响该地区海洋冰冻圈系统动力学的主要岩石圈热源的假设，收集的数据还将使我们能够完善当前的时间序列和地球动力学。驱动世界主要大陆裂谷系统之一的该项目的交付成果将是新的地理空间信息数据，包括该地区所有正在进行的地球物理网格，可通过 NSF 资助的数据公开获取。在获得地球化学和地质年代学后，剩余的岩石样本将存档在极地岩石存储库中。该项目还将培训 1 名博士后、2 名研究生和至少 3 名本科生。该奖项反映了 NSF 的法定使命，并已被视为。值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。