The relation between climate, glaciers, and lacustrine sedimentation in the american cordillera

山地冰川是气候变化的敏感指标。在前进过程中被冰川淹没的冰碛、边线和森林为重建过去的冰川活动提供了机会。前冰期湖泊沉积物是冰川波动的另一个有价值的代用物，因为更广泛的冰盖应增加受冰川侵蚀的底物的比例。与陆地冰川代用物相比，湖泊沉积物的一个优势是它们可以提供连续性。除了冰覆盖的长期变化外，冰川沉积物也可以用来推断有利于碎屑沉积物幕式输送到湖盆的水文气候条件。在利用这些独特的沉积记录重建冰川活动和洪水等事件方面取得进展，需要认识到沉积物储存和可利用性的变化在控制碎屑沉积速率方面所起的作用。在接下来的五年里，我计划推进我们对北美西部和巴塔哥尼亚的气候、冰川和下游河谷沉积之间关系的理解。我提出的研究有两个目标：1)在年到几十年的时间尺度上评估气候、冰川波动和前冰期沉积之间的关系；2)在几个世纪到几千年的时间尺度上记录碎屑沉积的控制。我提出的研究将有助于评估沉积物输出与冰川动力学之间的关系。考虑到气候、冰川营养和沉积物产量之间的强烈相互作用，这项工作将为高纬度地区冰川范围的长期变化和驱动这些变化的外部因素提供见解。全新世包括许多气候事件，为潜在的未来行为提供了重要的类似物。这些事件还为校准和验证一般和区域环流模型提供了有价值的情景。最后，本科生和研究生是成功进行拟议研究的必要条件。他们的参与应有助于尽量减少预计加拿大在今后十年高素质人员的短缺。

Mountain glaciers are sensitive indicators of climate change. Moraines, trimlines, and forests overrun by glaciers during an advance provide opportunities to reconstruct past glacier activity. Proglacial lake sediments represent another valuable proxy of glacier fluctuations because more extensive ice cover should increase the proportion of substrate subject to glacier erosion. An advantage that lake sediments afford over terrestrial glacier proxies is the continuity that they can provide. In addition to long-term changes in ice cover, glacigenic sediments can also be used to infer hydro-climatic conditions that favor episodic delivery of clastic sediments to the lake basin. Progress in the use of these unique sedimentary records to reconstruct glacier activity and events such as floods requires an appreciation of the role that changes in sediment storage and availability play in controlling clastic sedimentation rates. Over the next five years I plan to advance our understanding of the relation between climate, glaciers, and downvalley sedimentation in western North America and Patagonia. My proposed research has two objectives: 1) to asses the relation between climate, glacier fluctuations and proglacial sedimentation at time scales of years to decades; and 2) to document the controls of clastic sedimentation at time scales of centuries to millennia. The research that I propose will help assess the relation between sediment export and glacier dynamics. Given the strong interplay between climate, glacier nourishment, and sediment yield, this work will provide insight into long-term changes in glacier extent and the external factors that drive these changes at high latitudes. The Holocene Epoch includes numerous climate events that provide important analogues for potential future behavior. These events also provide valuable scenarios for calibrating and verifying general and regional circulation models. Finally, undergraduate and graduate students are integral to successfully undertake the proposed research. Their involvement should help minimize the projected Canadian deficit of highly qualified personnel in the next decade.