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Full-Text Articles in Glaciology

Isotopic Signature Of Massive, Buried Ice In Eastern Taylor Valley, Antarctica: Implications For Its Origin, Christopher B. Gardner, Melisa A. Diaz, Devin F. Smith, Andrew G. Fountain, Joseph S. Levy, W. Berry Lyons Dec 2022

Isotopic Signature Of Massive, Buried Ice In Eastern Taylor Valley, Antarctica: Implications For Its Origin, Christopher B. Gardner, Melisa A. Diaz, Devin F. Smith, Andrew G. Fountain, Joseph S. Levy, W. Berry Lyons

Geography Faculty Publications and Presentations

The coastal regions of the McMurdo Dry Valleys, Antarctica, contain deposits of the Ross Sea Drift, sedimentary material left from the Ross Sea ice sheet from the advance of the West Antarctic ice sheet during the Last Glacial Maximum. Much of this deposit is ice-cored, but data on the stable isotopic composition of water from this ice, which may contain a valuable climate archive, are sparse or incomplete. Widespread thermokarstic ground subsidence in this “coastal thaw zone” of the McMurdo Dry Valleys suggests that these potential records are rapidly being lost due to the melting of ground ice and permafrost. …


A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, H. W. Hunt, Andrew G. Fountain, Peter T. Doran, Hassan J. Basagic Jan 2010

A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, H. W. Hunt, Andrew G. Fountain, Peter T. Doran, Hassan J. Basagic

Geography Faculty Publications and Presentations

We developed a simulation model for terrestrial sites including sensible heat exchange between the atmosphere and ground surface, inter- and intra-layer heat conduction by rock and soil, and shortwave and longwave radiation. Water fluxes included snowmelt, freezing/thawing of soil water, soil capillary flow, and vapour flows among atmosphere, soil, and snow. The model accounted for 96-99% of variation in soil temperature data. No long-term temporal trends in soil temperature were apparent. Soil water vapour concentration in thawed surface soil in summer often was higher than in frozen deeper soils, leading to downward vapour fluxes. Katabatic winds caused a reversal of …


Surface Energy Balance And Melt Thresholds Over 11 Years At Taylor Glacier, Antarctica, Matthew James Hoffman, Andrew G. Fountain, Glen E. Liston Dec 2008

Surface Energy Balance And Melt Thresholds Over 11 Years At Taylor Glacier, Antarctica, Matthew James Hoffman, Andrew G. Fountain, Glen E. Liston

Geography Faculty Publications and Presentations

In the McMurdo Dry Valleys, Victoria Land, Antarctica, melting of glacial ice is the primary source of water to streams, lakes, and associated ecosystems. To understand geochemical fluxes and ecological responses to past and future climates requires a physically based energy balance model. We applied a one-dimensional model to one site on Taylor Glacier using 11 years of daily meteorological data and seasonal ablation measurements. Inclusion of transmission of solar radiation into the ice was necessary to accurately model summer ablation and ice temperatures. Results showed good correspondence between calculated and measured ablation and ice temperatures over the 11 years. …


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 …


Hydrologic Response To Extreme Warm And Cold Summers In The Mcmurdo Dry Valleys, East Antarctica, Peter T. Doran, Christopher P. Mckay, Andrew G. Fountain, Thomas H. Nylen, Diane M. Mcknight, Chris Jaros, John E. Barrett Jan 2008

Hydrologic Response To Extreme Warm And Cold Summers In The Mcmurdo Dry Valleys, East Antarctica, Peter T. Doran, Christopher P. Mckay, Andrew G. Fountain, Thomas H. Nylen, Diane M. Mcknight, Chris Jaros, John E. Barrett

Geography Faculty Publications and Presentations

The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- …


Biogeochemical Evolution Of Cryoconite Holes On Canada Glacier, Taylor Valley, Antarctica, Elizabeth A. Bagshaw, Martyn Tranter, Andrew G. Fountain, Kathleen A. Welch, Hassan J. Basagic, W. Berry Lyons Dec 2007

Biogeochemical Evolution Of Cryoconite Holes On Canada Glacier, Taylor Valley, Antarctica, Elizabeth A. Bagshaw, Martyn Tranter, Andrew G. Fountain, Kathleen A. Welch, Hassan J. Basagic, W. Berry Lyons

Geography Faculty Publications and Presentations

The cryoconite holes of the McMurdo Dry Valleys are simple, closed biogeochemical systems involving water, ice, mineral and organic debris, which serve as ecosystems for consortia of microorganisms. This study is the first to document the seasonal and annual chemical evolution of solutes in cryoconite holes. Samples of glacier ice, frozen cryoconite holes and those containing water were collected during the austral summer of 2005–2006. The isolation age was calculated from the excess Cl‾ in the holes, and varied from 0 to 5 years (a), consistent with the last hot summer when the cryoconite holes were open to the atmosphere. …


Biogeochemical Stoichiometry Of Antarctic Dry Valley Ecosystems, John E. Barrett, Ross A. Virginia, W. Berry Lyons, Diane M. Mcknight, John Charles Priscu, Peter T. Doran, Andrew G. Fountain, Diana H. Wall, D. L. Moorhead Feb 2007

Biogeochemical Stoichiometry Of Antarctic Dry Valley Ecosystems, John E. Barrett, Ross A. Virginia, W. Berry Lyons, Diane M. Mcknight, John Charles Priscu, Peter T. Doran, Andrew G. Fountain, Diana H. Wall, D. L. Moorhead

Geography Faculty Publications and Presentations

Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–10⁶ years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated …


A Strategy For Monitoring Glaciers, Andrew G. Fountain, Robert M. Krimmel, Dennis C. Trabant Jan 1997

A Strategy For Monitoring Glaciers, Andrew G. Fountain, Robert M. Krimmel, Dennis C. Trabant

Geography Faculty Publications and Presentations

Glaciers are important features in the hydrologic cycle and affect the volume, variability, and water quality of runoff. Assessing and predicting the effect of glaciers on water resources require a monitoring program to provide basic data for this understanding. The monitoring program of the U.S. Geological Survey employs a nested approach whereby an intensively studied glacier is surrounded by less intensively studied glaciers and those monitored solely by remote sensing. Ideally, each glacierized region of the United States would have such a network of glaciers. The intensively studied glacier provides a detailed understanding of the physical processes and their temporal …