Holocene glacier activity at the southwestern part of Hardangerjøkulen,central-southern Norway : evidence from lacustrine sediments

Abstract

Lacustrine sediments from Lake Isdalsvatn downstream from the southwestern margin of the plateau glacier Hardangerjøkulen, central-southern Norway, show that the lake received glacial meltwater until 7890 ± 95 BP. A thin, bluish-grey minerogenic silt layer probably reflects a short glacial (re)advance between 7005 ± 90 and 6835 ± 150BP. After the latter date, inflow of glacial meltwater ceased, indicating that small or, more probably, no glaciers existed on the southwestern Hard angerjøkulen plateau. A drop in organic content and a slight increase in detrital content inferred from magnetic susceptibility at 120cm depth in the core, may indicate some glacier activity in the catchment from about 3400 BP. Textural changes at 50cm depth indicate increased Neoglacial activity in the upper catchment area from 2265 ± 80 BP. Differences in glacier chronologies between the southern and northern sectors of Hardangerjøkulen may be explained partly by different glacier responses to the precipitation and wind distribution at opposite sides of the ice cap.