The Sensitivity of a Small Icecap to Climatic Fluctuations

ABSTRACT

The glacial chronology, obtained from proglacial lacustrine sediments, shows that Riukojietna, a small ice cap. disappeared or was small and inactive in the early-mid Holocene. A reactivation of the ice cap occurred around 2000 B.P. Riukojietna has retreated rapidly after a distinct maximum in extent in the beginning of the twentieth century. Measurements yielded negative net balances between 1985 and 1988. Differences in net balance seem to be caused primarily by fluctuating summer balances. Since Riukojietna has a relatively small vertical extent and is relatively low lying compared with cirque glaciers, it is much more sensitive to changes in the climate. Riukojietna is far from being in balance with the existing climate and will, if present trends continue, finally disappear.

Key words:

• Climatic fluctuations
• glacier variations
• mass balance
• lacustrine sediments