Some comments on glacier surges in eastern Svalbard

Abstract

Between 1936 and 1938 a great amount of ice flowed out from Sörfonna (the South Ice) on the south coast of Nordaustlandet. What had been an even slope of the ice sheet in 1936 developed into a badly crevassed glacier tongue by 1938, pushing approximately 20 km out to the sea along a front of 30 km. The new glacier was named Bråsvellbreen, which in fact means "rapid growth glacier", but because of World War II, no field investigations could be carried out until more than 10 years after its discovery.The majority of glaciers in eastern Vestspitsbergen have retreated during this century—a few, however, have advanced considerably during short periods and taken part in the general retreat during the rest of the time.Air photographs from 1924, 1938, 1956, and 1957 show that most of the ice edge in western Nordaustlandet has remained stable—Söre Franklinbreen, however, has shown large oscillations.The glaciers in the area belong to the sub-polar type, i.e. the 10-m ice temperature in the ablation area remains at about 8–10° below zero throughout the year, whereas the 10-m firn temperature in the accumulation area is at or very near freezing point.There are large variations in accumulation conditions from one Spitsbergen glacier to the other. The west coast of Vestspitsbergen is under the influence of mild and wet air masses from the Atlantic—the east coast is far more continental. The Nordaustlandet ice caps, on the other hand, receive most of their accumulation with winds from the Barents Sea. Annual net balance values of 80–120 g/cm2 are quite common on the eastern slopes of Austfonna (the East Ice), values of 70–90 g/cm2 have been observed along the crest of Sörfonna, and it is likely that large parts of the accumulation area of Bråsvellbreen itself receives an annual net balance of between 50 and 90 g/cm2.