Glacier change on Axel Heiberg Island, Nunavut, Canada

Abstract

AbstractHistorical records are valuable for assessing glacier change in the Canadian High Arctic. Ommanney’s (1969) detailed inventory of Axel Heiberg Island glaciers, based on photography from 1958–59, has been revisited, converted into digital format and compared to glacier extents mapped from 1999–2000 satellite imagery. Our results show that the island-wide ice coverage decreased by 15.92 km2 in the 42 year period, a loss of <1%. However, two trends are apparent: one of advance or minor retreat from basins hosting outlet glaciers from Müller and Steacie Ice Caps, and one of significant retreat, on the order of 50–80%, for independent ice masses, which include valley glaciers, mountain glaciers, glacierets, and ice caps smaller than 25 km2. If the contributions to ice advance of only three surging glaciers are removed, then the island-wide ice loss approaches 60 km2. Furthermore, it is notable that 90% of ice masses smaller than 0.2 km2 disappeared entirely during the 42 year study period, an observation confirmed by field studies. Successful predictions from the original inventory are highlighted and the likely mechanisms driving the observed advances and retreats are discussed.