Collaborative Research: Antarctic Airborne ElectroMagnetics (ANTAEM) - Revealing Subsurface Water in Coastal Antarctica

合作研究：南极机载电磁学 (ANTAEM) - 揭示南极洲沿海的地下水

• 批准号: 1643536
• 负责人: Peter Doran
• 金额: $ 20.24万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643536&HistoricalAwards=false
• 关键词: Collaborative; Research; Antarctic; Airborne; ElectroMagnetics

In Antarctica, millions of years of freezing have led to the development of hundreds of meters of thick permafrost (i.e., frozen ground). Recent research demonstrated that this slow freezing has trapped and concentrated water into local and regional briny aquifers, many times more salty than seawater. Because salt depresses the freezing point of water, these saline brines are able to persist as liquid water at temperatures well below the normal freezing point of freshwater. Such unusual groundwater systems may support microbial life, supply nutrients to coastal ocean and ice-covered lakes, and influence motion of glaciers. These briny aquifers also represent potential terrestrial analogs for deep life habitats on other planets, such as Mars, and provide a testing ground for the search for extraterrestrial water. Whereas much effort has been invested in understanding the physics, chemistry, and biology of surface and near-surface waters in cold polar regions, it has been comparably difficult to investigate deep subsurface aquifers in such settings. Airborne ElectroMagnetics (AEM) subsurface imaging provides an efficient way for mapping salty groundwater. An international collaboration with the University of Aarhus in Denmark will enable knowledge and skill transfer in AEM techniques that will enhance US polar research capabilities and provide US undergraduates and graduate students with unique training experiences. This project will survey over 1000 km2 of ocean and land near McMurdo Station in Antarctica, and will reveal if cold polar deserts hide a subsurface pool of liquid water. This will have significant implications for understanding cold polar glaciers, ice-covered lakes, frozen ground, and polar microbiology as well as for predictions of their response to future change. Improvements in permafrost mapping techniques and understanding of permafrost and of underlying groundwaters will benefit human use of high polar regions in the Antarctic and the Arctic.The project will provide the first integrative system-scale overview of subsurface water distribution and hydrological connectivity in a partly ice-free coastal region of Antarctica, the McMurdo Dry Valleys. Liquid water is relatively scarce in this environment but plays an outsized role by influencing, and integrating, biological, biogeochemical, glaciological, and geological processes. Whereas surface hydrology and its role in ecosystem processes has been thoroughly studied over the last several decades, it has been difficult to map out and characterize subsurface water reservoirs and to understand their interactions with regional lakes, glaciers, and coastal waters. The proposed project builds on the "proof-of-concept" use of AEM technology in 2011. Improvements in sensor and data processing capabilities will result in about double the depth of penetration of the subsurface during the new data collection when compared to the 2011 proof-of-concept survey, which reached depths of 300-400m. The first field season will focus on collecting deep soundings with a ground-based system in key locations where: (i) independent constraints on subsurface structure exist from past drilling projects, and (ii) the 2011 resistivity dataset indicates the need for deeper penetration and high signal-to-noise ratios achievable only with a ground-based system. The regional airborne survey will take place during the second field season and will yield subsurface electrical resistivity data from across several valleys of different sizes and different ice cover fractions.

在南极洲，数百万年的冰冻导致了数百米厚的永久冻土层（即冻土）的形成。最近的研究表明，这种缓慢的冰冻将水困住并浓缩到当地和区域的咸水含水层中，其咸度比海水高很多倍。由于盐会降低水的冰点，因此这些盐水能够在远低于淡水正常冰点的温度下以液态水形式持续存在。这种不寻常的地下水系统可能支持微生物的生命，为沿海海洋和冰雪覆盖的湖泊提供营养，并影响冰川的运动。这些咸水含水层也代表了其他行星（例如火星）上深层生命栖息地的潜在陆地类似物，并为寻找地外水提供了试验场。尽管人们在了解寒冷极地地区地表和近地表水的物理、化学和生物学方面投入了大量精力，但在这种情况下调查深层地下含水层却相对困难。机载电磁学 (AEM) 地下成像为绘制咸地下水图提供了一种有效的方法。与丹麦奥胡斯大学的国际合作将实现 AEM 技术的知识和技能转移，这将增强美国的极地研究能力，并为美国本科生和研究生提供独特的培训体验。该项目将调查南极洲麦克默多站附近超过 1000 平方公里的海洋和陆地，并将揭示寒冷的极地沙漠是否隐藏着地下液态水池。这对于了解寒冷的极地冰川、冰覆盖的湖泊、冻土和极地微生物学以及预测它们对未来变化的反应具有重要意义。永久冻土测绘技术的改进以及对永久冻土和底层地下水的了解将有利于人类对南极和北极高极地区的利用。该项目将首次对南极洲部分无冰沿海地区麦克默多干谷的地下水分布和水文连通性进行综合系统规模的概述。液态水在这种环境中相对稀缺，但通过影响和整合生物、生物地球化学、冰川和地质过程而发挥着巨大的作用。尽管过去几十年来对地表水文及其在生态系统过程中的作用进行了深入研究，但绘制和描述地下水库的特征以及了解它们与区域湖泊、冰川和沿海水域的相互作用仍然很困难。拟议项目以 2011 年 AEM 技术的“概念验证”应用为基础。与 2011 年概念验证勘测相比，传感器和数据处理能力的改进将导致新数据收集过程中地下穿透深度增加约一倍，2011 年概念验证勘测深度达到 300-400 m。第一个现场季节将侧重于利用地面系统在以下关键地点收集深部探测数据：(i) 过去的钻探项目对地下结构存在独立的限制，(ii) 2011 年电阻率数据集表明需要更深的穿透和只有利用地面系统才能实现的高信噪比。区域机载调查将在第二个野外季节进行，并将产生来自几个不同大小和不同冰盖部分的山谷的地下电阻率数据。

项目成果

Brief communication: The hidden labyrinth: deep groundwater in Wright Valley, Antarctica

简讯：隐藏的迷宫：南极洲莱特谷的深层地下水

• DOI: 10.5194/tc-16-4977-2022
• 发表时间: 2022
• 期刊: The Cryosphere
• 作者: Dugan, Hilary A.;Doran, Peter T.;Grombacher, Denys;Auken, Esben;Bording, Thue;Foged, Nikolaj;Foley, Neil;Mikucki, Jill;Virginia, Ross A.;Tulaczyk, Slawek
• 通讯作者: Tulaczyk, Slawek

Comparison of ground-based and airborne transient electromagnetic methods for mapping glacial and permafrost environments: Cases from McMurdo Dry Valleys, Antarctica

用于绘制冰川和永久冻土环境的地基和机载瞬变电磁方法的比较：来自南极洲麦克默多干谷的案例

• DOI: 10.1016/j.coldregions.2022.103578
• 发表时间: 2022
• 期刊: Cold Regions Science and Technology
• 影响因子: 4.1
• 作者: Madsen, Line M.;Bording, Thue;Grombacher, Denys;Foged, Nikolaj;Foley, Neil;Dugan, Hilary A.;Doran, Peter T.;Mikucki, Jill;Tulaczyk, Slawek;Auken, Esben
• 通讯作者: Auken, Esben

Induced polarization effects in airborne transient electromagnetic data collected in the McMurdo Dry Valleys, Antarctica

在南极洲麦克默多干谷收集的机载瞬变电磁数据中的感应极化效应

• DOI: 10.1093/gji/ggab148
• 发表时间: 2021
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Grombacher, Denys;Auken, Esben;Foged, Nikolaj;Bording, Thue;Foley, Neil;Doran, Peter T;Mikucki, Jill;Dugan, Hilary A;Garza-Giron, Ricardo;Myers, Krista
• 通讯作者: Myers, Krista

Thermal legacy of a large paleolake in Taylor Valley, East Antarctica, as evidenced by an airborne electromagnetic survey

机载电磁调查证明，东南极洲泰勒谷一个大型古湖的热遗产

• DOI: 10.5194/tc-15-3577-2021
• 发表时间: 2021
• 期刊: The Cryosphere
• 作者: Myers, Krista F.;Doran, Peter T.;Tulaczyk, Slawek M.;Foley, Neil T.;Bording, Thue S.;Auken, Esben;Dugan, Hilary A.;Mikucki, Jill A.;Foged, Nikolaj;Grombacher, Denys
• 通讯作者: Grombacher, Denys

Evidence for Pathways of Concentrated Submarine Groundwater Discharge in East Antarctica from Helicopter-Borne Electrical Resistivity Measurements

• DOI: 10.3390/hydrology6020054
• 发表时间: 2019-06-01
• 期刊: HYDROLOGY
• 影响因子: 3.2
• 作者: Foley, Neil;Tulaczyk, Slawek M.;Virginia, Ross
• 通讯作者: Virginia, Ross