Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics

该项目将调查东南极托滕冰川和莫斯科大学冰架的海洋成分。这个系统至关重要，因为它排干了东南极冰盖的八分之一，其体积相当于潜在海平面上升近7米，比整个西南极冰盖都大。这个几乎完全未开发的地区是唯一一个最大、最不为人所知的潜在不稳定的海洋冰川系统。尽管对西南极冰盖的海洋系统进行了严格的审查，但人们对托滕冰川系统知之甚少。这项研究将大大增加该地区现有的稀少的海洋和海洋地质学和地球物理学数据，并将显著促进对这个知之甚少的冰川系统及其对环境变化的潜在敏感反应的了解。独立的天基平台表明托滕冰川系统的质量正在加速丧失。最近对奥罗拉冰下盆地进行的航空地球物理调查为测量到的表面变化提供了冰下背景，并表明托滕冰川是至少两个以前的冰流制度中最重要的排水途径。然而，人们对离岸背景的了解要少得多。来自附近陆架/坡折点的有限实际海洋学数据表明，在明显通往托滕冰川的槽口厚厚的底层内存在修正的环极深水，这表明冰下可能有相对温暖的水流入，这一过程被认为是导致西南极冰盖接地线撤退的原因。该项目将对该区域进行以船舶为基础的海洋地质和地球物理调查，并结合实际海洋学研究，以评估冰川系统的近期和长期行为及其与邻近海洋系统的关系。这一努力将补充对其他南极冰架的研究、南极半岛附近的海洋学研究，以及正在进行的冰盖和其他海洋模型的开发。

This project will investigate the marine component of the Totten Glacier and Moscow University Ice Shelf, East Antarctica. This system is of critical importance because it drains one-eighth of the East Antarctic Ice Sheet and contains a volume equivalent to nearly 7 meters of potential sea level rise, greater than the entire West Antarctic Ice Sheet. This nearly completely unexplored region is the single largest and least understood marine glacial system that is potentially unstable. Despite intense scrutiny of marine based systems in the West Antarctic Ice Sheet, little is known about the Totten Glacier system. This study will add substantially to the meager oceanographic and marine geology and geophysics data available in this region, and will significantly advance understanding of this poorly understood glacial system and its potentially sensitive response to environmental change.Independent, space-based platforms indicate accelerating mass loss of the Totten system. Recent aerogeophysical surveys of the Aurora Subglacial Basin, which contains the deepest ice in Antarctica and drains into the Totten system, have provided the subglacial context for measured surface changes and show that the Totten Glacier has been the most significant drainage pathway for at least two previous ice flow regimes. However, the offshore context is far less understood. Limited physical oceanographic data from the nearby shelf/slope break indicate the presence of Modified Circumpolar Deep Water within a thick bottom layer at the mouth of a trough with apparent access to Totten Glacier, suggesting the possibility of sub-glacial bottom inflow of relatively warm water, a process considered to be responsible for West Antarctic Ice Sheet grounding line retreat. This project will conduct a ship-based marine geologic and geophysical survey of the region, combined with a physical oceanographic study, in order to evaluate both the recent and longer-term behavior of the glacial system and its relationship to the adjacent oceanographic system. This endeavor will complement studies of other Antarctic ice shelves, oceanographic studies near the Antarctic Peninsula, and ongoing development of ice sheet and other ocean models.