Bennett Island - Glaciers

Glaciers

Bennett Island has the largest permanent ice cover within the De Long Islands. In 1987, the permanent ice cover of this island consisted of four separate glaciers that had a total area of 65.87 km² (25.43 mi²). All of these glaciers were perched on high, basaltic plateaus bounded by steep scarp-like slopes.

In 1992, Dr. Verkulich and others named these glaciers as the De Long East, De Long West, Malyy, and Toll glaciers. With an area of 55.5 km² (21.4 mi²) in 1987, Toll Glacier was the largest of them. It occupied the center of Bennett Island; had an elevation of 380 to 390 m (1,250 to 1,280 ft) above mean sea level; and was 160 to 170 m (524 to 560 ft) thick at its center. It had an outlet glacier, West Seeberg Glacier, from which ice flowed downhill from Toll Glacier into the sea. The next largest glacier was De Long East Glacier with an area of 5.16 km² (1.99 mi²) in 1987. It laid about 420 m (1,380 ft) above mean sea level at the southeast end of Bennett Island and had a thickness of 40 to 45 m (130 to 147 ft). Adjacent to De Long East Glacier laid the De Long West Glacier with an are of 1.17 km² (0.45 mi²); an elevation of 330 to 340 m (1,080 to 1,115 ft) above mean sea level; and a thickness of 40 m (130 ft) in 1987. Malyy Glacier, with an area of 4.04 km² (1.56 mi²) in 1987, occupied a basaltic plateau at an elevation of 140 to 160 m (460 to 525 ft) above mean sea level on the northeast end of Bennett Island and was 40 to 50 m (130 to 164 ft) thick. In 1987, all of these glaciers were shrinking in volume and had been so for the past 40 years.

Of the glaciers described by Dr. Verkulich and others, Dr. Glazovskiy discusses only the Tollya Ice Cap, which Dr. Verkulich and others referred to as "Toll Glacier". In 1996, it had an area of 54.2 km² and a mean elevation of 384 m (1,260 ft) above sea level. Its equilibrium line altitude was at an elevation of 200 m (660 ft) above sea level.

According to Alekseev, Anisimov and Tumskoy, and Makeyev and others, the glaciers found on Bennett and other islands of the De Long Islands are remnants of small passive ice caps formed during the Last Glacial Maximum (Late Weichselian Epoch) about 17,000 to 24,000 BP. At the time that these ice caps formed, the De Long Islands were major hills within a large subaerial plain, called the Great Arctic Plain, that now lies submerged below the Arctic Ocean and East Siberian Sea.