Stability of marine basins in the Antarctic Peninsula Ice Sheet from remote sensing

该项目将评估埃尔斯沃斯陆地（连接南极西部和南极半岛冰盖的地区）下面的海洋冰盖盆地目前和未来的稳定性。众所周知，海洋冰原盆地，定义为冰原在海平面以下的部分，特别容易退缩，因此对未来全球海平面上升有很大的潜在影响（DeConto和Pollard, 2016; Mercer, 1978），这些过程在南极洲西部的阿蒙森海海湾（Bingham等人，2017；Scambos等人，2017）中得到了很多研究。尽管过去十年的一些研究也引起了人们的注意，西南极洲的埃尔斯沃思地也容易受到海洋冰盖不稳定的影响（Bingham等人，2012），目前也显示出这种情况正在发生的迹象（Hogg等人，2017；Wouters等人，2015），但该地区仍然相对缺乏数据，无法很好地估计其未来的退缩率和海平面贡献。解决这一基本的知识差距，并阐明由埃尔斯沃斯地冰的潜在退缩造成的近期海平面上升的危险，是这个项目的重点。该项目的主要目的是评估位于南极洲西部和南极半岛之间的埃尔斯沃斯陆海盆地近期（未来200年）的稳定性。这包括以下目标：为Ellsworth Land编制来自地球观测数据集的当代冰川变化（冰面速度、地表高程和接地线的变化）时间序列；2. 追踪横跨埃尔斯沃思地的冰川地平线（被视为等时线，或年龄相等的表面），从而对其深层冰施加年龄限制，利用邻近层追踪的年龄限制，并与西南极洲冰芯年龄-深度剖面相联系——最终目的是限制该地区最古老的冰，从而为其过去的稳定性提供线索；3. 探索机器学习方法在地球物理数据和/或从地球观测数据编制当代变化时间序列中的应用。

This project will assess the current and future stability of marine ice-sheet basins that collectively underlie Ellsworth Land, the region that connects the West Antarctic and Antarctic Peninsula Ice Sheets. It is well known that marine ice-sheets basins, defined as the parts of the ice sheets that are grounded below sea level, are particularly vulnerable to retreat and therefore have significant potential to contribute to future global sea-level rise (DeConto and Pollard, 2016; Mercer, 1978), and these processes are much studied in West Antarctica's Amundsen Sea Embayment (Bingham et al., 2017; Scambos et al., 2017). Despite some studies over the last decade also drawing attention to West Antarctica's Ellsworth Land also being vulnerable to marine ice-sheet instability (Bingham et al., 2012) and currently showing signs of this being underway (Hogg et al., 2017; Wouters et al., 2015), the region remains relatively data-poor for good estimates of its future retreat rates and sea-level contributions. Addressing this fundamental knowledge gap and elucidating the dangers to near-future sea-level rise posed by potential retreat of ice from Ellsworth Land form the focus of this project. Aim, objectives and methods of the proposed research The main aim of the project is to assess the near-term (200 years into the future) stability of the Ellsworth Land marine basin lying between West Antarctica and the Antarctic Peninsula. This comprises the following objectives: 1. To compile for Ellsworth Land time series of contemporary glaciological change (changes to ice-surface velocity, surface elevation and the grounding line) from Earth Observation datasets; 2. To track englacial horizons (treated as isochrones, or surfaces of equal age) across Ellsworth Land, and thereby place age constraints on its deep ice, using age constraints from adjacent layer-tracking and links to West Antarctica's ice core age-depth profiles - with the ultimate aim of constraining what is the oldest ice in the region, and hence give clues to its past stability; 3. To explore the application of machine-learning methods for tracking englacial layers in geophysical data and/or compiling time series of contemporary changes from Earth Observation data.