Soil temperatures and stability of ice-cemented ground in the McMurdo Dry Valleys, Antarctica

Year-round temperature measurements at 1600 m elevation during 1994 in the Asgard Range Antarctica, indicate that the mean annual frost point of the ice-cemented ground, 25 cm below the surface, is −21.7 ± 0.2°C and the mean annual frost point of the atmosphere is −27.5 ± 1.0°C. The corresponding me...

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Bibliographic Details
Published in:Antarctic Science
Main Authors: McKay, Christopher P., Mellon, Michael T., Friedmann, E. Imre
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1998
Subjects:
Ice
Online Access:http://dx.doi.org/10.1017/s0954102098000054
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102098000054
Description
Summary:Year-round temperature measurements at 1600 m elevation during 1994 in the Asgard Range Antarctica, indicate that the mean annual frost point of the ice-cemented ground, 25 cm below the surface, is −21.7 ± 0.2°C and the mean annual frost point of the atmosphere is −27.5 ± 1.0°C. The corresponding mean annual temperatures are −24.9°C and −23.3°C. These results imply that there is a net flux of water vapour from the ice to the atmosphere resulting in a recession of the ice-cemented ground by about 0.4–0.6 mm yr 1 . The level of the ice-cemented permafrost is about 12 cm below the level of dry permafrost. The summer air temperatures would have to increase about 7°C for thawing temperatures to just reach the top of the subsurface ice. Either subsurface ice at this location is evaporating over time or there are sporadic processes that recharge the ice and maintain equilibrium over long timescales.