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

美洲山脉气候、冰川和湖泊沉积之间的关系

• 批准号: 261619-2009
• 负责人: Menounos, Brian
• 金额: $ 2.19万
• 依托单位: University of Northern British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=525307
• 关键词: relation; between; climate; glaciers; lacustrine

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.

山地冰川是气候变化的敏感指标。冰碛、纵倾线和森林在冰川前进过程中被冰川覆盖，为重建过去的冰川活动提供了机会。 冰前湖沉积物代表了冰川波动的另一个有价值的代理，因为更广泛的冰盖应该增加受冰川侵蚀的基底的比例。湖泊沉积物相对于陆地冰川替代物的一个优势是它们可以提供连续性。除了冰盖的长期变化，冰川沉积物也可以用来推断水文气候条件，有利于碎屑沉积物到湖盆的幕式输送。 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，需要了解沉积物储存和可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，我计划加深我们对北美西部和巴塔哥尼亚气候、冰川和河谷沉积之间关系的理解。我提出的研究有两个目标：1）在几年到几十年的时间尺度上评估气候，冰川波动和冰前沉积之间的关系; 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和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，这项工作将深入了解冰川范围的长期变化以及在高纬度地区推动这些变化的外部因素。全新世时期包括许多气候事件，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大气和区域环流模式提供了宝贵的情景。最后，本科生和研究生是不可或缺的成功进行拟议的研究。他们的参与应有助于尽量减少预计加拿大在未来十年中缺乏高素质人才的情况。