A CONTINUOUS HOLOCENE GLACIER RECONSTRUCTION OF THE HØGTUVBREEN GLACIER, NORTHERN NORWAY

Arctic mountain glaciers have decreased dramatically in extent over the last decades as a consequence to higher temperature and/or reduced winter precipitation as snow. These glaciers are sensitive to changes in the climate system, and can therefore give valuable information about past climate conditions. Several studies have been conducted on past variation in glacier size in northern Scandinavia. The emphasis of this study is on Høgtuvbreen, a coastal mountain glacier in northern Norway (Presently 3.0 km² – LIA max: 11.2 km²). The glacier on this site is believed to be highly sensitive to changes in atmospheric circulation due to the proximity to the prevailing snow bearing westerly winds in the region. An outlet from the Høgtuvbreen glacier is reconstructed on the basis of downstream glaciolacustrine cores and lichen-dated moraines. Three ¹⁴C-dated cores have been subject to high-resolution analyses of physical and geochemical properties. The dataset has then undergone a PCA analysis to investigate anomalies in the dataset and extract the most probable sediment parameter that indicates glacier activity in the catchment. The DBD indicate major glacial advances around 8150-7640, 3800-3670, 3270-3100, 2730-2600, 2550-2400, 2130-1880, 1620-1020, 910-840 and 800-270 b2k. Ten moraine steps are defined as glacier advance positions. Of these, seven moraines were suited for lichen dating. The conversion from lichen size to age is based on a novel method of comparing different methods of defining maximum lichen size and growth rate curves. The results from the lichen dating indicate that the most distal moraine was formed around AD 1743 ± 55, while the successively more proximal moraines were formed around AD: 1766 ± 48, 1857 ± 29, 1866 ± 27, 1903 ± 21, 1963 ± 14 and 1977 ± 10. With the present rate of decrease, the glacier is expected to disappear completely within the next 20-30 years.