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Portland State University

Geography Faculty Publications and Presentations

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Ablation (Aerothermodynamics)

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Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Temporal Variations In Physical And Chemical Features Of Cryoconite Holes On Canada Glacier, Mcmurdo Dry Valleys, Antarctica, Andrew G. Fountain, Thomas H. Nylen, Martyn Tranter, Elizabeth A. Bagshaw Jan 2008

Temporal Variations In Physical And Chemical Features Of Cryoconite Holes On Canada Glacier, Mcmurdo Dry Valleys, Antarctica, Andrew G. Fountain, Thomas H. Nylen, Martyn Tranter, Elizabeth A. Bagshaw

Geography Faculty Publications and Presentations

Cryoconite holes in the McMurdo Dry Valleys are ice-lidded, thus isolating the pools of water from the atmosphere and from potential surface melt. Hourly measurements of ice and water temperature and water electrical conductivity (EC) were recorded to broadly characterize the physical and chemical changes on daily to seasonal timescales. Overall, subsurface ice/water temperatures were typically several degrees warmer than air temperatures, underscoring the importance of subsurface solar heating. At no time was surface melt observed and the holes melted from within. Detailed differences in the timing and magnitude of both temperature and EC variations during melt-out and freezeup existed …


Water Flow Through Temperate Glaciers, Andrew G. Fountain, Joseph S. Walder Aug 1998

Water Flow Through Temperate Glaciers, Andrew G. Fountain, Joseph S. Walder

Geography Faculty Publications and Presentations

Understanding water movement through a glacier is fundamental to several critical issues in glaciology, including glacier dynamics, glacier-induced floods, and the prediction of runoff from glacierized drainage basins. To this end we have synthesized a conceptual model of water movement through a temperate glacier from the surface to the outlet stream. Processes that regulate the rate and distribution of water input at the glacier surface and that regulate water movement from the surface to the bed play important but commonly neglected roles in glacier hydrology. Where a glacier is covered by a layer of porous, permeable firn (the accumulation zone), …