Antarctic Ice Front, Shelf and Grounding Line Dynamics from High-resolution, Commercial Satellite Imagery and Elevation Data

对海平面上升的预测取决于南极洲冰架对海洋和大气变化的反应。这些冰架的变薄和坍塌可能会导致冰盖迅速失控的消退。因此，了解控制冰架稳定性的过程至关重要。许多这样的过程，如冰裂和破裂，发生得太快或太小，在大多数卫星图像中看不到，但也太大，太偏远，无法在实地测量。美国国家科学基金会支持的极地地理空间中心(PGC)汇编了从商业卫星收集的高分辨率卫星图像和地表高度数据的海量档案，这些数据跨越了十多年，可以填补这一观测空白，并提高我们对冰架变化的理解。该项目将结合其他数据集，首次全面应用商业卫星图像，以衡量南极冰架的变化和对冰盖稳定性的潜在影响。该项目还将包括本科生和研究生，并利用伯德极地和气候研究中心的现有资源进行教育和推广方案。该项目将使用PGC商业卫星图像档案和高分辨率数字高程模型，以高空间和时间分辨率测量一组关键南极冰架的表面特征、流量和应变率以及表面高程变化。将使用一套测量目标来评估CSI解决接地线、冰架和冰川混杂的重大变化的能力。该小组将利用这些测量方法来解决悬而未决的科学问题，包括冰架和接地线之间的相互作用、冰架和混杂的结构和动态演变以及冰锋的稳定性。我们将把我们的测量与互补的数据集结合起来，例如来自陆地卫星和哨兵卫星星座的ICESat-2测高和冰速，以及来自NASA冰桥行动的空中测量，以提供更全面的变化记录。该项目将制作包括三维飞行在内的视觉效果，用于外展活动，以激发不同人群对南极科学的兴趣。该项目将支持一名研究生的培训，并将开发在冰川学和相关应用中利用CSI的方法。最后，结果将有助于指导PGC未来的CSI任务和数据生产战略，以最好地服务于科学界的目标。该奖项反映了NSF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。

Predictions of sea-level rise depend on the response of Antarctica’s ice shelves to changes in the ocean and atmosphere. Thinning and collapse of these ice shelves may lead to rapid, runaway retreat of the ice sheet. It is therefore critical to understand the processes controlling ice-shelf stability. Many of these processes, such as ice rifting and crevassing, occur too quickly or are too small to be seen in most satellite images, but are also too large and remote to measure in the field. The NSF-supported Polar Geospatial Center (PGC) has compiled a massive archive of high-resolution satellite imagery and surface-elevation data collected from commercial satellites, spanning over a decade, that can fill this observational gap and improve our understanding of ice-shelf change. This project will provide a first, comprehensive application of commercial satellite imagery, in combination with other datasets, to measure changes in Antarctic ice shelves and potential impacts to ice-sheet stability. This project will also include undergraduate and graduate students and leverage existing resources at the Byrd Polar and Climate Research Center for education and outreach programs.The project will use the PGC archive of commercial satellite imagery (CSI) and high-resolution digital elevation models to measure surface features, flow and strain rates, and surface elevation change, with high spatial and temporal resolution, at a set of critical Antarctic ice shelves. A set of measurement objectives will be used to assess the capabilities of CSI for resolving significant changes in grounding lines, ice shelves, and ice mélange. The team will use these measurements to address outstanding science questions regarding the interaction between the ice shelf and grounding line, the structural and dynamic evolution of ice shelves and mélange, and ice-front stability. We will combine our measurements with complementary datasets, such as ICESat-2 altimetry and ice velocity from Landsat and Sentinel satellite constellations, as well as airborne measurements from NASA’s Operation IceBridge, to provide a more comprehensive record of change. This project will produce visuals, including three-dimensional fly-throughs, that will be used in outreach activities to spark interest in Antarctic science among diverse populations. This project will support the training of a graduate student and will develop methods for utilizing CSI in glaciology and related applications. Finally, the results will help guide the PGC’s future CSI tasking and data production strategies to best serve science community objectives.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.