Authors: Erik Schiefer*, Northern Arizona University, Darrell Kaufman, Northern Arizona University, Nicholas McKay, Northern Arizona University, Michael Retelle, Bates College and University Centre in Svalbard, Al Werner, Mt Holyoke College, Steve Roof, Hampshire College
Topics: Geomorphology, Paleoenvironmental Change, Polar Regions
Keywords: fluvial sediment, geomorphology, climate change, Lake Linnévatnet, Svalbard
Session Type: Paper
Start / End Time: 8:00 AM / 9:40 AM
Room: Napoleon B2, Sheraton 3rd Floor
Presentation File: No File Uploaded
Records of sediment yield are important for environmental reconstruction because they are an index of catchment erosion and sediment delivery, which are controlled by geologic, geomorphic, and climatic history. We explored a collection of complementary yield records that span many orders of magnitude in temporal scale for the glacierized Lake Linné (78.04°N 18.82°E) catchment, which is situated in a high Arctic region experiencing rapid environmental change and where sediment transfer data is sparse. Multivariate rating curve models from three seasons of stream gauging during late summer periods of high glacier melt show the importance of hourly to daily fluctuations of discharge and short-term climate controls. Sediment volumes and stratigraphies in seasonal and annual lake sediment traps indicate that annual yields are typically dominated by a short period of spring snowmelt. Strong seasonal variations in sediment delivery to the lake bottom result in varve (annually laminated) deposition across much of the lake. Multivariate modelling of varve-based flux showed significant hydroclimatic correlations, involving seasonal temperatures, rainfall, and discharge, for overlapping periods of instrumental data. Variability through the LIA and MWP reflects strong, short-term periodicities that may relate to climatic oscillations, but we did not otherwise detect clear intermediate (multi-century to multi-decadal) trends. Millennial-scale variability in sedimentation reflects long-term glacier presence and extent, as well as delta progradation and threshold stabilization. These findings have significant implications for future sediment yield in the catchment and, perhaps more broadly, in glacierized catchments through the Arctic. Results are contrasted with other Arctic records currently being developed.