Collaborative Research: Sediment and Stability: Quantifying the Effect of Moraine Building on Greenland Tidewater Glaciers

合作研究：沉积物和稳定性：量化冰碛建筑对格陵兰潮水冰川的影响

• 批准号: 2234520
• 负责人: Ginny Catania
• 金额: $ 26.31万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2234520&HistoricalAwards=false
• 关键词: Collaborative; Research; Sediment; Stability; Quantifying

The Greenland Ice Sheet (GrIS) is presently the largest contributor of added mass to rising sea levels, recently surpassing contributions from alpine glaciers and ice caps, the Antarctic Ice Sheet and land water storage. Mass loss is concentrated at the periphery of the ice sheet where low-lying outlet glaciers drain into the warm ocean surrounding Greenland. Despite overall mass loss, outlet glaciers of the Greenland Ice Sheet have experienced significant variability in the amount of glacier-front retreat observed over the satellite era. This variability remains unexplained because there are many processes that can influence the position of the front of an outlet glacier and these environments are difficult to obtain observations in. This project aims to collect observations from the front of three outlet glaciers in Greenland where retreat variability has been observed. The goal of this project is to determine if the deposition of sediment at the ice-ocean boundary is responsible for the observed variability in glacier retreat. Further, this project will measure the rates and types of sedimentation processes present at the active glacier front as well as the past position of each glacier observed in the satellite record. The project will also take observations of basic glacier parameters that may be responsible for variations in the rates of sedimentation between glaciers.The overarching goal of this project is to understand the fundamental drivers of ice sheet change and stability through focusing on a poorly understood, observation-limited part of the system: the sediment budget. Moraine building at glacier termini may enable larger steady-state glaciers than would be possible in the absence of sediment, as is evident in high-meltwater settings (e.g., Alaska). However, processes and rates of proglacial sedimentation are poorly known, especially in Greenland, where morainal banks are abundant but where the influence of bank formation on ice sheet dynamics is unconstrained. The central hypothesis of this project is that morainal bank sedimentation can stabilize or delay retreat for some glacier systems. This project will test this hypothesis with observations of four processes that contribute to moraine building at three neighboring Greenland glaciers with sharply different dynamic histories and geometries. The project will deploy a novel remotely operated vehicle (ROV Nereid) designed for surveying and sampling in deep, ice marginal environments to obtain high-resolution geological, geophysical, and oceanographic measurements at the ice-sediment-ocean interface. This project will train graduate students, with a focus on mentorship and diversifying the geosciences.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.

格陵兰冰盖（GrIS）目前是海平面上升的最大贡献者，最近超过了高山冰川和冰盖、南极冰盖和陆地蓄水的贡献。质量损失集中在冰盖的外围，那里低洼的出口冰川流入格陵兰岛周围温暖的海洋。尽管整体质量损失，格陵兰冰盖的出口冰川在卫星时代观察到的冰川前缘退缩量经历了显着变化。这种变化仍然无法解释，因为有许多过程可以影响出口冰川前部的位置，而这些环境很难获得观测结果。该项目旨在收集格陵兰岛三个出口冰川前部的观测数据，这些冰川的退缩变化已经存在。被观察到。该项目的目标是确定冰海边界沉积物的沉积是否是观测到的冰川退缩变化的原因。此外，该项目将测量活跃冰川前缘的沉积过程的速率和类型，以及卫星记录中观察到的每个冰川的过去位置。该项目还将对可能导致冰川之间沉积速率变化的基本冰川参数进行观测。该项目的总体目标是通过关注人们知之甚少的观测来了解冰盖变化和稳定性的基本驱动因素。 -系统的有限部分：沉积物预算。在冰川末端形成的冰碛可能会形成比没有沉积物时更大的稳态冰川，这一点在高融水环境（例如阿拉斯加）中很明显。然而，人们对冰期沉积的过程和速率知之甚少，特别是在格陵兰岛，那里的冰碛堤丰富，但冰堤的形成对冰盖动力学的影响却不受限制。该项目的中心假设是，冰碛岸沉积可以稳定或延迟某些冰川系统的退缩。该项目将通过观察四个过程来检验这一假设，这些过程有助于三个相邻格陵兰冰川的冰碛形成，这三个冰川的动态历史和几何形状截然不同。该项目将部署一种新型遥控潜水器（ROV Nereid），设计用于在深层冰缘环境中进行勘测和采样，以获得冰-沉积物-海洋界面的高分辨率地质、地球物理和海洋学测量结果。该项目将培训研究生，重点是指导和地球科学多样化。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。