Collaborative Research: Glacier-sediment interactions during onset of tidewater glacier retreat

合作研究：潮水冰川退缩开始时冰川与沉积物的相互作用

• 批准号: 2051846
• 负责人: Jason Amundson
• 金额: $ 56.69万
• 依托单位: University of Alaska Southeast Juneau Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2051846&HistoricalAwards=false
• 关键词: Collaborative; Research; Glacier; sediment; interactions

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Tidewater glaciers are glaciers that flow into the ocean. Although tidewater glaciers make up a small percent of all the glaciers in the world, they are important for climate because they contain large volumes of ice and because they can change rapidly. Our ability to predict future sea level rise depends on how well we understand these glaciers. Most tidewater glaciers are currently retreating. Until recently, one of the few tidewater glaciers that was advancing was the Taku Glacier in Southeast Alaska. Photos and satellite imagery indicate that the glacier has recently started to retreat, but it is unknown how quickly the glacier will retreat. This project will investigate the early stages of the glacier’s retreat by using time-lapse photography, drone surveys, satellite data, and computer models. The project is expected to lead to a better understanding of tidewater glacier retreat and improve our ability to predict sea level rise. The project will support early career researchers and students, who will also be involved in a field course at the glacier. Tidewater glaciers are known to undergo cycles of slow, centennial-scale advance and rapid, decadal-scale retreat that are driven by processes occurring at the glacier-ocean interface, including iceberg calving, submarine melting, and sediment deposition and erosion. These cycles can occur in a steady climate, but climate can modify the timescales of advance and retreat as well as act as a trigger. Since the advance phase is longer than the retreat phase, in a steady climate one would expect the majority of tidewater glaciers to be advancing. This is not the case at present, as the majority of tidewater glaciers around the world are retreating or in a quasi-stable configuration. Until recently, Taku Glacier in Southeast Alaska was one of the rare advancing tidewater glaciers. Recent observations indicate that, due to a warming climate, the glacier is now thinning over its entire area and has begun to retreat off of the terminal moraine that it developed and prograded over the past 125 years. This project will investigate the processes by which a tidewater glacier transitions into retreat, and the evolving glacier sensitivity to climate during this transition, by integrating field and remote sensing observations of Taku Glacier with numerical modeling experiments. By advancing understanding of tidewater glacier stability, the project will lead to improved estimates of sea level rise. The project will support a postdoctoral scholar and undergraduate research assistants, and field work for this project will occur in parallel with a field course that will be held at the glacier terminus.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.

该奖项是根据2021年《美国救援计划法》的全部或部分资助的（公共法117-2）。水域冰川是流入海洋的冰川。尽管潮水冰川占世界所有冰川的一小部分，但它们对于气候很重要，因为它们含有大量的冰，并且可以迅速变化。我们预测未来海平面上升的能力取决于我们对这些冰川的了解程度。大多数潮水冰川目前正在撤退。直到最近，阿拉斯加东南部的塔岛冰川是少数几个潮水冰川之一。照片和卫星图像表明冰川最近开始撤退，但是冰川将撤退的速度尚不清楚。该项目将使用延时摄影，无人机调查，卫星数据和计算机模型来研究冰川撤退的早期阶段。预计该项目将使人们更好地了解潮水冰川静修，并提高我们预测海平面上升的能力。该项目将支持早期的职业研究人员和学生，他们还将参与冰川的野外课程。已知潮水冰川会经历缓慢，百年级的前进和快速，十年级的静修的周期，这些静修是由冰川界面处发生的过程驱动的，包括冰山产犊，海底融化，沉积物和沉积物的沉积和侵蚀。这些循环可以在稳定的气候中发生，但是气候可以改变前进和撤退的时间尺度，并充当触发。由于前进阶段比撤退阶段更长，因此在稳定的气候下，人们会期望大多数潮水冰川前进。目前并非如此，因为世界各地的大多数潮水冰川正在撤退或以准稳定的配置。直到最近，阿拉斯加东南部的Taku冰川还是罕见的潮汐冰川之一。最近的观察结果表明，由于气候变暖，冰川现在在整个区域变薄，并已开始从过去125年中开发和编程的终端撤退。该项目将研究潮汐水冰川转变为撤退的过程，以及通过将塔克冰川与数值建模实验的田间和远程敏感性观察整合到这种过渡期间不断发展的冰川敏感性。通过促进对潮水冰川稳定性的了解，该项目将改善对海平面上升的估计。该项目将支持博士后科学和本科研究助理，该项目的现场工作将与将在Glacier Terminus举行的现场课程并行进行。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估审查审查标准来通过评估来获得支持的。