A 1200-YEAR RECORD OF GLACIER FLUCTUATIONS AND CLIMATE AT LANGSTRANDTINDAN, LOFOTEN, NORTHERN NORWAY

Arctic glaciers have globally experienced a negative mass balance because of the changing climate over the past decades. The Lofoten archipelago at 68°N has one of the largest air temperature anomalies in the world relative to latitude; this is because of the warm waters of the Norwegian Atlantic Current (NAC). Hence, the climate in Lofoten is very sensitive to the ocean-atmosphere interaction between variations in the magnitude and strength of the NAC and the prevailing westerly wind direction. Here we present the first high-resolution late-Holocene glacier record from the Lofoten archipelago in northern Norway. The study is based on analyses of lacustrine sediments in the proglacial lake Kveitvikvatnet (31 m a.s.l.), and glacial-geomorphological mapping of the ~4.2 km² large surrounding catchment. At present, Kveitvikvatnet receives glacial meltwater from three small cirque glaciers. In total, five sediment cores have been retrieved from the lake. The cores (~2-5 m long) have been examined for input of glacial-derived sediments by use of various physical sediment properties like X-ray fluorescence (XRF), magnetic susceptibility (MS), grain-size analyses, bulk density (DBD) and loss-on-ignition (LOI). Former glacier extent has been reconstructed by use of aerial photos, terrestrial photos and glacial-geomorphological mapping. Based on AMS radiocarbon dating the cores cover the last 1200 years, including both the Little Ice Age (LIA) and the Medieval Warm Period (MWP). We suggest that the input of silt- and clay fractions to the lake is reflecting the glacier activity in the basin. We find a high increase of silt and clay fractions in the core between 1200-600 and 300-0 cal. yr BP. By linking the various sediment proxies to known glacier frontal positions and independent temperature-reconstructions from the area, the glacier-fluctuations and climate have been reconstructed at Langstrandtindan for the last 1200 years.