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

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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.