The near−surface ice thermal structure of the Waldemarbreen, Svalbard

Abstract

The near−surface ice thermal structure of the Waldemarbreen, a 2.5−square km glacier located at 78 N1 2E in Spitsbergen, Svalbard, is described here. Traditional glacio− logical mass balance measurements by stake readings and snow surveying have been con− ducted annually since 1996. The near−surface ice temperature was investigated with auto− matic borehole thermistors in the ablation and accumulation areas in 2007-2008. The mean annual surface ice temperatures (September-June) of the ablation area were determined to be −4.7C at 1 m depth and −2.5C at 9 m. For the accumulation area, they were −3.0 Ca t 2 m, and −2.3C at 10 m depth between September and August. On the Waldemarbreen, at 10 m depth, the mean annual near−surface ice temperature was 4.0C above the mean annual air temperature in the accumulation area. The Waldemarbreen may thus be classified as a polythermal type with cold ice which is below the pressure melting point and a temperate ice layer in the bottom sections of the glacier and with a temperate surface layer only during summer seasons. At a depth of 10 m, temperatures are of the order of −2C to −3C. Key wor ds: Arctic, Spitsbergen, ice temperature, thermal regime, glacier.