Preliminary results of field investigations and analysis of air photos of the Tjörn Valley region (Wedel Jarlsberg Land, Spitsbergen) are presented. The youngest, Quaternary deposits and landforms were mapped. Reconstruction of the last advance and retreat of the Tjörndals Glacier is also described.
The present paper contains the results of geomorphological investigations carried out by the author during the llnd Polar Expedition of the Scientific Society of the Students of the Department of Geography and Regional Studies, Warsaw University, to the northwest part of Nordenskiöld Land (West Spitsbergen) in the summer of 1980. The present elaboration discusses the glacial forms and deposits which arose during previous stays of the glacier on this area. Particular attention was paid to the disposition of erratics, which permitted the determination of the directions of the transgression of the young Quaternary glaciations.
Geological and geomorphological studies in Kaffiöyra and Hermansenöya (Oscar II Land, northwestern Spitsbergen), completed with radiocarbon datings, indicated that the Early Vistulian (Weichselian) Glaciation of presumable regional significance, occupied the whole area. Marine transgression during and after deglaciation reached at least to 65 m a.s.l. Glacioisostatic uplift and marine regression in Kaffiöyra resulted in development of older raised beaches at 52-65 m a.s.l. During the Late Vistulian, Kaffiöyra was occupied partly by outlet glaciers (Aavatsmark, Elise and Andreas), while the Dahl Glacier covered Hermansenöya. Extents of these glaciers were much greater than during the Little Ice Age. Marine transgression during deglaciation reached to 46-48 m a.s.l. at about 12-11.5 ka B.P. During glacioisostatic emergence at 11.5-9 ka B.P., ten younger raised marine beaches were formed in Kaffiöyra. Traces of a probable glacial episode at 3-2.5 ka B.P. were noted in forefields of the Aavatsmark and the Elise glaciers only. In forefields of all glaciers in Kaffiöyra there are deposits and landforms formed during glacial advances of the Little Ice Age and the following continuous retreat. The Aavatsmark Glacier was the only one to indicate surge type readvances at that time.
Arctic glaciers depend on supply of moisture, mostly from the Atlantic. The snowline is remarkably high in northeast Siberia, remote from this source. Because of differential solar radiation receipt, local glaciers have a northward−facing tendency throughout the Arctic. This is weaker than in dry mid−latitudes but low sun angles enhance the effects of shading, compensating for the broader range of aspects ( i.e. slope directions) illuminated in summer. Statistics from the World Glacier Inventory and other sources show that mass balance differences between slopes of different aspects give both more glaciers, and lower glaciers, facing the favoured direction: usually North. This is clear, for example, for local glaciers (and for all small glaciers) in central Spitsbergen and in Axel Heiberg Island. Wind effects (drifting snow to leeward slopes) are much less important, except in northwest Europe from Norway to Novaya Zemlya which is under the strong influence of westerly winds, greatest in the Polar and Sub−polar Urals. A thorough analysis is provided of aspect data for local glaciers within and near the Arctic Circle, and of variation in glacier mid−altitude with aspect and position. There is consistency between mean glacier aspect (in terms of numbers) and aspect with lowest glaciers, everywhere except in Wrangel Island.