COLLABORATIVE RESEARCH: Elevation Change Anomalies in West Antarctica and Dynamics of Subglacial Water Transport Beneath Ice Streams and their Tributaries

Tulaczyk/0636970该奖项支持一个研究海拔变化异常(以下简称ECA)的项目，ECA是在西南极冰盖(WAIS)罗斯海区域内几个地点的遥感图像中观察到的椭圆形、5至10公里的区域。在这些异常中，地表高程的变化速度最高可达每天~1到~2厘米，明显快于周围地区。这些异常被认为是由于几千米尺度的冰下水坑的充填和排出造成的。这个项目的学术价值在于，这些ECA代表了一个前所未有的窗口，让人们了解现代南极冰盖下难以捉摸的排水动态世界。尽管与正常的陆地条件相比，冰层下的水通量很小，但它们在控制快速冰流以及潜在的冰盖稳定性方面发挥着重要作用。缺乏对次冰盖水动力学的观测约束是对冰流和冰盖定量建模进展的最重要限制之一。这些模型对于评估未来的冰盖质量平衡和重建冰盖对过去气候变化的反应是必要的。ECAs显示的动态冰盖下水的运输也可能对冰下湖泊和其他冰下环境的研究产生影响，这些环境可能蕴藏着适应这种极端条件的生命。该项目的更广泛影响是，它将为一名博士后研究员(UW)、两名女博士生(UCSC)和至少三名本科生(UCSC)提供高级培训机会，她们将加强极地科学的多样性。项目产出将涉及广泛的科学和社会利益，如未来全球海平面变化和极地地区对气候变化的反应。自由科学记者道格拉斯·福克斯有兴趣参加第一个实地考察季，为科普杂志撰写专题文章，并促进该项目以及整个南极科学向大众媒体的曝光。

Tulaczyk/0636970This award supports a project to study elevation change anomalies (henceforth ECAs), which are oval-shaped, 5-to-10 km areas observed in remote sensing images in several locations within the Ross Sea sector of the West Antarctic Ice Sheet (WAIS). Within these anomalies, surface elevation changes at rates of up to ~1 to ~2 cm per day, significantly faster than in surrounding regions. These anomalies are thought to result from filling and draining of multi-kilometer-scale subglacial water pockets. The intellectual merit of this project is that these ECA's represent an unprecedented window into the elusive world of water drainage dynamics beneath the modern Antarctic ice sheet. Although subglacial water fluxes are small compared to normal terrestrial conditions, they play an important role in controlling fast ice streaming and, potentially, stability of the ice sheet. The dearth of observational constraints on sub-ice sheet water dynamics represents one of the most important limitations on progress in quantitative modeling of ice streams and ice sheets. Such models are necessary to assess future ice sheet mass balance and to reconstruct the response of ice sheets to past climate changes. The dynamic sub-ice sheet water transport indicated by the ECAs may have also implications for studies of subglacial lakes and other subglacial environments, which may harbor life adapted to such extreme conditions. The broader impacts of this project are that it will provide advanced training opportunities to one postdoctoral fellow (UW), two female doctoral students (UCSC), who will enhance diversity in polar sciences, and at least three undergraduate students (UCSC). Project output will be relevant to broad scientific and societal interests, such as the future global sea level changes and the response of Polar Regions to climate changes. Douglas Fox, a freelance science journalist, is interested in joining the first field season to write feature articles to popular science magazines and promote the exposure of this project, and Antarctic Science in general, to mass media.