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Article
Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers
Journal of Glaciology
  • Matthew J. Hoffman, Los Alamos National Laboratory
  • Andrew G. Fountain, Portland State University
  • Glen E. Liston, Colorado State University - Fort Collins
Document Type
Article
Publication Date
4-1-2014
Subjects
  • Meltwater -- Antarctica -- McMurdo Dry Valleys,
  • Glaciers -- Antarctica -- McMurdo Dry Valleys,
  • Ablation (Aerothermodynamics)
Abstract

The McMurdo Dry Valleys, southern Victoria Land, East Antarctica, are a polar desert, and melt from glacial ice is the primary source of water to streams, lakes and associated ecosystems. Previous work found that to adequately model glacier ablation and subsurface ice temperatures with a surface energy-balance model required including the transmission of solar radiation into the ice. Here we investigate the contribution of subsurface melt to the mass balance of (and runoff from) Dry Valley glaciers by including a drainage process in the model and applying the model to three glacier sites using 13years of hourly meteorological data. Model results for the smooth glacier surfaces common to many glaciers in the Dry Valleys showed that sublimation was typically the largest component of surface lowering, with rare episodes of surface melting, consistent with anecdotal field observations. Results also showed extensive internal melting 5-15 cm below the ice surface, the drainage of which accounted for 50% of summer ablation. This is consistent with field observations of subsurface streams and formation of a weathering crust. We identify an annual cycle of weathering crust formation in summer and its removal during the 10 months of winter sublimation.

Description

This is the publisher's PDF archived with permission.

This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.

DOI
10.3189/2014JoG13J095
Persistent Identifier
http://archives.pdx.edu/ds/psu/12177
Citation Information
Hoffman, M. J., Fountain, A. G., & Liston, G. E. (2014). Near-surface internal melting: a substantial mass loss on Antarctic Dry Valley glaciers. Journal of Glaciology, 60(220), 361.