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

积雪或积雪含水层是在经历夏季强烈表面融化和高降雪量的冰川地区形成的地下融水储存区域。含水层会导致水力破裂，从而加速流动或引发冰架不稳定，从而增加冰盖的质量损失。最近在格陵兰岛发现了广泛的含水层。已使用新的卫星和机载遥感技术对这些区域进行建模和绘制地图。在南极洲，南极半岛威尔金斯冰架的一系列灾难性解体以前被归因于表面融化和盐水渗透的影响，现在被认为与可能受到长期海洋膨胀刺激的积雪含水层一致，从而加剧了冰架的水力破裂。该项目将验证(来自格陵兰岛使用的相同测绘方法)南极洲确实存在这种含水层的推断。该团队将调查两个极有可能的地点：威尔金斯冰架和南部乔治六世冰架。这项为期两年的研究将描述两个现场的降雪特征，钻探浅(最大为~60米)冰芯，检查积雪坑(~2米)，并安装两个AMIGOS(自动气象局-冰-地球物理观测系统)站，其中包括天气、GPS和降雪温度传感器，在恢复之前将收集和传输至少一年的测量结果。实地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与实地观测的特性相结合，以进一步探索积雪含水层的范围和相关的上雪层条件。本研究将为三位初出茅庐的科学家提供宝贵的经验。计划通过实地博客、社交媒体帖子、K-12演示文稿和公开演讲等方式开展推广活动，让公众参与到S南极科学探索和发现团队中来。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智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.