Antarctic Firn Aquifers: Extent, Characteristics, and Comparison with Greenland Occurrences

南极冷杉含水层：范围、特征以及与格陵兰岛的比较

• 批准号: 1745116
• 负责人: Ted Scambos
• 金额: $ 26.19万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1745116&HistoricalAwards=false
• 关键词: Antarctic; Firn; Aquifers; Extent; Characteristics

Snow or firn aquifers are areas of subsurface meltwater storage that form in glaciated regions experiencing intense summer surface melting and high snowfall. Aquifers can induce hydrofracturing, and thereby accelerate flow or trigger ice-shelf instability leading to increased ice-sheet mass loss. Widespread aquifers have recently been discovered in Greenland. These have been modelled and mapped using new satellite and airborne remote-sensing techniques. In Antarctica, a series of catastrophic break-ups at the Wilkins Ice Shelf on the Antarctic Peninsula that was previously attributed to effects of surface melting and brine infiltration is now recognized as being consistent with a firn aquifer--possibly stimulated by long-period ocean swell--that enhanced ice-shelf hydrofracture. This project will verify inferences (from the same mapping approach used in Greenland) that such aquifers are indeed present in Antarctica. The team will survey two high-probability sites: the Wilkins Ice Shelf, and the southern George VI Ice Shelf. This two-year study will characterize the firn at the two field sites, drill shallow (~60 m maximum) ice cores, examine snow pits (~2 m), and install two AMIGOS (Automated Met-Ice-Geophysics Observing System) stations that include weather, GPS, and firn temperature sensors that will collect and transmit measurements for at least a year before retrieval. Ground-penetrating radar survey in areas surrounding the field sites will track aquifer extent and depth variations. Ice and microwave model studies will be combined with the field-observed properties to further explore the range of firn aquifers and related upper-snow-layer conditions. This study will provide valuable experience for three early-career scientists. An outreach effort through field blogging, social media posts, K-12 presentations, and public lectures is planned to engage the public in the team?s Antarctic scientific exploration and discovery.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.

雪或雪含水层是在经历夏季强烈地表融化和高降雪量的冰川地区形成的地下融水储存区域。含水层可以诱发水力压裂，从而加速流动或引发冰架不稳定，导致冰盖质量损失增加。最近在格陵兰岛发现了大面积的含水层。利用新的卫星和机载遥感技术对这些区域进行了模拟和绘制。在南极洲，在南极半岛的威尔金斯冰架上发生的一系列灾难性的破裂，以前被认为是由于表面融化和盐水渗透的影响，现在被认为是与一个坚硬的含水层相一致的——可能是由长期的海洋膨胀刺激的——这加剧了冰架的水力破裂。这个项目将证实（从格陵兰岛使用的相同测绘方法得出的）推论，即这种含水层确实存在于南极洲。该小组将调查两个可能性很大的地点：威尔金斯冰架和乔治六世南部冰架。这项为期两年的研究将在两个现场对冰芯进行表征，钻取浅（最大约60米）冰芯，检查雪坑（约2米），并安装两个AMIGOS（自动met - ice -地球物理观测系统）站，其中包括天气、GPS和冰芯温度传感器，这些传感器将在检索前收集和传输至少一年的测量数据。在油田周围地区的探地雷达调查将跟踪含水层的范围和深度变化。冰和微波模型研究将结合现场观测的性质，进一步探索firn含水层的范围和相关的上层雪层条件。本研究将为三位早期科学家提供宝贵的经验。计划通过现场博客，社交媒体帖子，K-12演示和公开讲座来吸引公众参与团队。5 .南极科学探索和发现。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。