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。这些冰架的变薄和崩溃可能导致冰盖迅速、失控的退缩。因此，了解控制冰架稳定性的过程至关重要。其中许多过程，如冰裂和裂缝，发生得太快或太小，在大多数卫星图像中看不到，但也太大和遥远，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）已经汇编了一个庞大的高分辨率卫星图像和从商业卫星收集的表面高程数据档案，跨越十多年，可以填补这一观测空白，并提高我们对冰架变化的理解。该项目将首次全面应用商业卫星图像，结合其他数据集，测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计划。该项目将使用商业卫星图像（CSI）和高分辨率数字高程模型的PGC档案来测量表面特征，流量和应变率，以及表面高程变化，具有高空间和时间分辨率，一组关键的南极冰架。将使用一组测量目标来评估CSI解决接地线、冰架和冰混合物重大变化的能力。该团队将使用这些测量来解决有关冰架和接地线之间的相互作用，冰架和混合物的结构和动态演变以及冰锋稳定性的突出科学问题。我们将联合收割机将我们的测量结果与补充数据集相结合，例如ICESat-2高度测量和来自Landsat和Sentinel卫星星座的冰速度，以及NASA冰桥行动的空中测量结果，以提供更全面的变化记录。该项目将制作视觉材料，包括三维飞行模拟器，用于宣传活动，以激发不同人群对南极科学的兴趣。该项目将支助一名研究生的培训，并将制订在冰川学和有关应用中利用CSI的方法。最后，研究结果将有助于指导PGC未来的CSI任务和数据生产策略，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，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.