Glacier surges in West Spitsbergenl

Surges constitute a common form of glacier advance in Spitsbergen. The fastest movement observed is that of the Negri Glacier, with an advance of -12 km in less than a year. Observations on the Finsterwalder Glacier indicate that the ice flow is too small to maintain a steady-state slope. At intervals, of the order of 100 years, the glacier will balance this build-up by surging. A small surging glacier in the Dickson Valley has a sheet of refrozen meltwater in the front. This refrozen meltwater is possibly generated by the surge. Surges are frequent phenomena in Spitsbergen; in fact they constitute a common form of glacier advance. The following is an outline of some of the best documented surges. Recherche Glacier on Bellsund made a large advance in 1839. The glacier was described at that time by the French Recherche Expedition as being heavily crevassed and the ice front was 3 km beyond its present position. Fridtjov Glacier on the north side of Bellsund was observed in 1858 by Torell (1 869). The glacier was apparently then about to begin a surge, and shell-bearing clay banks had been ploughed up from the sea bottom along its front. In 1861 when the glacier was next visited the front of the glacier had advanced over the whole of Fridtjov Harbour and out into Van Mijenfjorden, a distance of some 6 km. Savstrom Glacier on the north side of Isfjord was visited by a Swedish expedition in 1882 and again in 1896. During the 14-year interval the glacier front had advanced about 6 km across the fjord and onto Coraholmen. By 1896 it had apparently been retreating for several years. Wahlenberg Glacier also on the northern side of Isfjord advanced about 6 km in 1908. Von Post Glacier in innermost Isfjord was mapped photogrammetrically in 1924 and 1932. During that period the northern arm of the glacier surged; the snout advanced about 3 km, simultaneously compressing the eastern arm to less than half its original width and