Meltwater systems of past ice sheets: implications for ice sheet dynamics, meltwater routing and landscape change

过去冰盖的融水系统：对冰盖动力学、融水路径和景观变化的影响

• 批准号: RGPIN-2016-04018
• 负责人: Brennand, Tracy
• 金额: $ 1.75万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708749
• 关键词: Meltwater; systems; past; ice; sheets

Present-day ice sheets are melting, and the meltwater generated by them is contributing to sea level rise. Numerical ice sheet models are being used to predict future changes, though the linkages between ice sheet hydrology, ice dynamics and climate remain unclear. My research program provides empirical verification data (e.g., past ice sheet margins, meltwater channel type and character) vital for improving these models and their predictions, and for unraveling the history of past ice sheets. Specifically, the research in this application will: (1) develop and test a new classification of eskers (sediment casts of ice-walled meltwater channels) that will provide verification data for ice sheet models, allow more robust reconstructions of past ice sheet dynamics, assist remote predictive mapping in Canada's North, and guide aggregate and mineral exploration; and (2) quantify the amount of water stored in proglacial lakes at the margins of the last ice sheet to cover western Canada (Cordilleran Ice Sheet) and determine where they were dammed and when and how they drained in order to reconstruct past ice sheet decay, provide verification data for numerical ice sheet models and allow assessment of landscape change associated with these events. In sum, the results generated by this program are vital to predicting the future behaviour of present-day ice sheets, and will inform our understanding of past ice sheet hydrology and dynamics and landscape evolution. In addition, past meltwater systems left behind important aggregate resources, which are often sampled during drift prospecting campaigns and can form important aquifers. Understanding sediment transport within these systems and thus being able to predict textural changes or transport distances within them will facilitate more cost effective exploration or more defensible resource development. HQP training will result in much needed knowledge transfer to government and industry and facilitate environmentally-responsible development.

今天的冰盖正在融化，由它们产生的融化的水正在导致海平面上升。数值冰盖模型正被用来预测未来的变化，尽管冰盖水文、冰动力学和气候之间的联系仍不清楚。我的研究计划提供了经验验证数据(例如，过去的冰盖边缘、融化水通道类型和特征)，这些数据对于改进这些模型和它们的预测以及揭开过去冰盖的历史至关重要。具体地说，本应用程序中的研究将： (1)开发和测试新的ESKERS分类(冰墙融化水道的沉积物投射)，该分类将为冰盖模型提供验证数据，允许更有力地重建过去的冰盖动力学，协助加拿大北部的遥感预测制图，并指导集料和矿产勘探；以及 (2)对覆盖加拿大西部的最后一个冰盖(科迪勒兰冰盖)边缘的冰川湖泊中储存的水量进行量化，并确定它们在哪里筑坝以及何时和如何排水，以恢复过去的冰盖退化，为数值冰盖模型提供核实数据，并允许评估与这些事件有关的地貌变化。 总而言之，该项目产生的结果对于预测当今冰盖的未来行为至关重要，并将有助于我们了解过去的冰盖水文、动力学和景观演变。此外，过去的融水系统留下了重要的聚合资源，这些资源经常在漂移勘探活动中进行采样，并可能形成重要的含水层。了解这些系统内的沉积物传输，从而能够预测它们内部的结构变化或传输距离，将有助于更具成本效益的勘探或更具防御性的资源开发。HQP培训将导致向政府和行业转移急需的知识，并促进对环境负责的发展。