NSFGEO-NERC:Collaborative Research: Chemistry and Biology under Low Flow Hydrologic Conditions Beneath the Greenland Ice Sheet Revealed through Naturally Emerging Subglacial Water

NSFGEO-NERC：合作研究：通过自然涌出的冰下水揭示格陵兰冰盖下方低流量水文条件下的化学和生物学

• 批准号: 2039582
• 负责人: Trinity Hamilton
• 金额: $ 27.49万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2039582&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Collaborative; Research; Chemistry

This project is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/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, each Agency funds the proportion of the budget and the investigators associated with its own component of the work.Weathering is an important process that releases nutrients that are essential for life from rocks and minerals in the Earth’s surface. This project seeks to understand the effect of large glaciers on weathering processes beneath the Greenland Ice Sheet and the consequences for life. During summer, nutrients and other products are flushed out of the Greenland Ice Sheet with water from melting ice. While these products have been sampled in spring and summer, it is not known how weathering processes are different during winter. In this project, researchers will sample the seasonal ice that forms in front of two of Greenland’s glacial outlets, Isunnguata Sermia and Leverett Glacier, during the freezing months to assess the chemistry and microbiology processes that reflect wintertime conditions beneath the ice sheet – periods when input of fresh meltwater is minimal. These samples will increase knowledge of winter conditions under the Greenland Ice Sheet and help better understand the interior portions of the ice sheet which are largely inaccessible. Such information will help in assessing past conditions, when colder atmospheric conditions resulted in minimal meltwater input through the ice sheet and to the glacial bed. These analyses will inform understanding of the role of glaciers on earth’s nutrient cycles presently, under past ice age conditions, and in a future deglaciating world.The Greenland Ice Sheet is a major exporter of biologically important elements to the world’s oceans. However, most of our knowledge of chemical and biological fluxes from the ice sheet comes from the summer outflux of outlet glaciers whose channelized waters contact only a limited portion of the glacier bed. The majority of the glacier-bed interface contains slow-flowing, distributed waters not representative of this flux. The project will test the hypothesis that overwinter chemical and biological processes under outlets of the Greenland Ice Sheet differ substantially from summer outflow and represent a window into widespread, but typically inaccessible, distributed flow. The principal sample collection method will be early spring coring of naled ice that forms at glacial termini from wintertime subglacial flow. Chemical, mineralogical, and biological constituents of this flow will be compared to material emerging from the initial, peak, and terminal phases of the melt season. Elsewhere in the Arctic, the chemistry of frozen overwinter subglacial material shows significant limitation in oxygen or sediment supply compared with even the first spring melt, supporting the idea that naled ice reveals a unique overwinter system. The naled ice and outflow of Isunnguata Sermia and Leverett Glacier will be sampled over two years. These West Greenland outlets differ by more than an order of magnitude in the size of the catchments they drain, thereby testing the effect of scale on biogeochemistry. Naled ice structure will be characterized by ground penetrating radar and ice borehole temperature profiles. The aqueous geochemistry, stable isotopes of carbonate and sulphate, and mineralogy of the suspended sediment of ice and water will be assessed. These analyses will document changes in the mineral flux and supply of atmospheric gases at the glacial bed between winter low flow conditions and peak summer melt. Microbial abundance, diversity, metagenomics, and stable isotopes of biomass will also be measured to understand the concomitant relationship between geochemical conditions and biological communities. Researchers will incorporate findings into a number of outreach efforts including developing a new curriculum module for the Center for Earth and Environmental Sciences, providing research opportunities for underrepresented students as part of the Bridge to Research Program and preparing hands-on activities for the Market Science Program.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.

该项目由国家科学基金会的地球科学局（NSF/GEO）和英国国家环境研究委员会（UKRI/NERC）共同资助，并通过NSF/GEO-GEO-NERC首席代理机构协议。该协议允许该机构提交和同行评审的一项联合提案，其调查员的预算比例最大。成功确定奖励后，每个机构都为预算的比例和与其自己的工作组成部分相关的调查人员提供了资金。开采是一个重要的过程，可以释放出地球表面上岩石和矿物质至关重要的养分。该项目旨在了解大型冰川对格陵兰冰盖下的风化过程的影响以及对生活的后果。在夏季，养分和其他产品从格陵兰冰盖上冲出了融化的水。尽管这些产品在春季和夏季进行了采样，但尚不清楚冬季风化过程如何不同。在该项目中，研究人员将在冰冻的几个月内，在格陵兰岛两个冰川出口，Isunguata Sermia和Leverett Glacier面前形成的季节性冰，以评估反映冰期下方的冬季条件的化学和微生物学过程 - 新鲜融化材料的输入很小。这些样本将增加格陵兰冰盖下冬季条件的知识，并有助于更好地了解冰盖的内部部分，这些冰盖基本上无法访问。当较冷的大气条件导致通过冰盖和冰川床导致最小的融化输入时，这些信息将有助于评估过去的条件。这些分析将使人们了解冰川在过去的冰河时代条件下以及未来的退化世界中的地球营养周期中的作用。格陵兰冰盖是世界上海洋上重要元素的主要出口商。但是，我们对冰盖化学和生物通量的大多数知识都来自出口冰川的夏季出口，其通道水仅接触了冰川床的有限部分。大多数冰川床界面包含不代表这种通量的慢流量，分布的水。该项目将检验以下假设：格陵兰冰片插座下的越冬化学和生物过程与夏季出口大致不同，并代表了一个窗口，但通常无法访问，但通常无法访问，分布式流量。主要样品收集方法将是冬季冰山下冰川末端形成的naled冰的早春芯。该流量的化学，矿物学和生物学构成将与从熔体季节的初始，峰和末端相位出现的物质进行比较。在北极的其他地方，与第一个弹簧熔体相比，冷冻越冬的冰底冰色材料的氧气或沉积物供应显着限制，这支持了naled冰揭示了独特的越冬系统的想法。 Isunguata Sermia和Leverett Glacier的Nal冰和出口将在两年内进行采样。这些西部格陵兰的插座的不同程度不超过其排水的集水区的数量级，从而测试了尺度对生物地球化学的影响。 naled冰结构的特征是地面穿透性辐射和冰孔温度曲线。将评估地球化学水性地球化学，稳定的碳酸盐和硫酸盐同位素以及冰和水悬浮沉积物的矿物学。这些分析将记录矿物通量的变化，并在冬季低流量条件和夏季峰值融化之间的冰川床上的大气床供应。还将测量微生物丰度，多样性，宏基因组学和稳定的生物量同位素，以了解地球化学条件与生物群落之间的伴随关系。研究人员将将发现纳入许多宣传工作，包括为地球与环境科学中心开发新的课程模块，为代表性不足的学生提供研究机会，这是研究计划的桥梁的一部分，并为市场科学计划做好了动态活动。该奖项颁发了NSF的法定任务，并通过评估了Infectian the Intellitial and Intformitial and Intperiatial and Intfulitial and Intfultial and Interviatial and Intfulitial的支持。