Spatial variations in the geochemistry of glacial meltwater streams in the Taylor Valley, Antarctica

2010 ◽  
Vol 22 (6) ◽  
pp. 662-672 ◽  
Author(s):  
Kathleen A. Welch ◽  
W. Berry Lyons ◽  
Carla Whisner ◽  
Christopher B. Gardner ◽  
Michael N. Gooseff ◽  
...  
Keyword(s):  
Chemical Weathering ◽  
Freezing Point ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Stream Chemistry ◽  
Glacial Meltwater ◽  
Taylor Valley ◽  
Air Temperatures ◽  
Wide Range ◽  
Long Term Ecological Research

AbstractStreams in the McMurdo Dry Valleys, Antarctica, flow during the summer melt season (4–12 weeks) when air temperatures are close to the freezing point of water. Because of the low precipitation rates, streams originate from glacial meltwater and flow to closed-basin lakes on the valley floor. Water samples have been collected from the streams in the Dry Valleys since the start of the McMurdo Dry Valleys Long-Term Ecological Research project in 1993 and these have been analysed for ions and nutrient chemistry. Controls such as landscape position, morphology of the channels, and biotic and abiotic processes are thought to influence the stream chemistry. Sea-salt derived ions tend to be higher in streams that are closer to the ocean and those streams that drain the Taylor Glacier in western Taylor Valley. Chemical weathering is an important process influencing stream chemistry throughout the Dry Valleys. Nutrient availability is dependent on landscape age and varies with distance from the coast. The streams in Taylor Valley span a wide range in composition and total dissolved solids and are surprisingly similar to a wide range of much larger temperate and tropical river systems.

scholarly journals Glacier mass balances (1993–2001), Taylor Valley, McMurdo Dry Valleys, Antarctica

2006 ◽  
Vol 52 (178) ◽  
pp. 451-462 ◽  
Author(s):  
Andrew G. Fountain ◽  
Thomas H. Nylen ◽  
Karen L. MacClune ◽  
Gayle L. Dana
Keyword(s):  
Mass Balance ◽  
Piecewise Linear ◽  
Objective Assessment ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Mass Balances ◽  
Missing Measurements ◽  
Wind Speeds ◽  
Taylor Valley ◽  
Air Temperatures

AbstractMass balances were measured on four glaciers in Taylor Valley, Antarctica, from 1993 to 2001. We used a piecewise linear regression, which provided an objective assessment of error, to estimate the mass balance with elevation. Missing measurements were estimated from linear regressions between points and showed a significant improvement over other methods. Unlike temperate glaciers the accumulation zone of these polar glaciers accumulates mass in summer and winter and the ablation zone loses mass in both seasons. A strong spatial trend of smaller mass-balance values with distance inland (r2 = 0.80) reflects a climatic gradient to warmer air temperatures, faster wind speeds and less precipitation. Annual and seasonal mass-balance values range only several tens of millimeters in magnitude and no temporal trend is evident. The glaciers of Taylor Valley, and probably the entire McMurdo Dry Valleys, are in equilibrium with the current climate, and contrast with glacier trends elsewhere on the Antarctic Peninsula and in temperate latitudes.

Climate and Hydrologic Variations and Implications for Lake and Stream Ecological Response in the McMurdo Dry Valleys, Antarctica

2003 ◽  
Author(s):  
Kathleen A. Welch ◽  
W. Berry Lyons
Keyword(s):  
New Zealand ◽  
Climatic Change ◽  
High Latitude ◽  
Lake Level ◽  
Climate Changes ◽  
Global Climate ◽  
Mcmurdo Dry Valleys ◽  
Polar Regions ◽  
Dry Valleys ◽  
Long Term Ecological Research

Because polar regions may amplify what would be considered small to moderate climate changes at lower latitudes, Weller (1998) proposed that the monitoring of high latitude regions should yield early evidence of global climate change. In addition to the climate changes themselves, the connections between the polar regions and the lower latitudes have recently become of great interest to meteorologists and paleoclimatologists alike. In the southern polar regions, the direct monitoring of important climatic variables has taken place only for the last few decades, largely because of their remoteness. This of course limits the extent to which polar records can be related to low latitude records, even at multiyear to decadal timescales. Climatologists and ecologists are faced with the problem that, even though these high latitude regions may provide important clues to global climatic change, the lengths of available records are relatively short. The McMurdo Dry Valleys Long-Term Ecological Research (MCM LTER) program was established in 1993. This program built on the monitoring begun in the late 1960s by researchers from New Zealand, who collected records of climate, lake level, and stream discharge in the Wright Valley, Antarctica. Griffith Taylor’s field party obtained the first data related to lake level in 1903 as part of Scott’s Discovery expedition. Analysis of the more recent data from the New Zealand Antarctic and MCM LTER programs when compared to the 1903 datum indicates that the first half of the twentieth century was a period of steadily increasing streamflows, followed in the last half of the century by streamflows that have resulted in more slowly increasing or stable lake levels (Bomblies et al. 2001). Thus, meteorological and hydrological records generated by the MCM LTER research team, when coupled with past data and the ecological information currently being obtained, provide the first detailed attempt to understand the connection between ecosystem structure and function and climatic change in this region of Antarctica. In addition, the program helps to fill an important gap in the overall understanding of climatic variability in Antarctica.

scholarly journals A temperature-index model of stream flow at below-freezing temperatures in Taylor Valley, Antarctica

2005 ◽  
Vol 40 ◽  
pp. 76-82 ◽  
Author(s):  
Amy F. Ebnet ◽  
Andrew G. Fountain ◽  
Thomas H. Nylen ◽  
Diane M. Mcknight ◽  
Christopher L. Jaros
Keyword(s):  
Melting Rate ◽  
Coefficient Of Determination ◽  
Dry Valleys ◽  
The South ◽  
Index Model ◽  
The North ◽  
Taylor Valley ◽  
Air Temperatures ◽  
Glacial Runoff ◽  
Summer Temperatures

AbstractWe model runoff from glaciers in the McMurdo Dry Valleys, Antarctica, with summer (December–January) average air temperatures from 1990 to 2002 for the purpose of estimating decades- to millennial-scale glacial runoff into Lakes Fryxell, Hoare and Bonney. The relationship between summer temperatures and melt is found to be exponential near the melting temperature. We propose a variety of simple models that are calibrated using measured discharge from a number of streams draining from ten glaciers in Taylor Valley. The surface melting rate is constrained by mass-balance measurements from four of the glaciers. A model based solely on temperature produced good results (coefficient of determination, r2 = 0.71) for the south-facing glaciers, but poor results for the north-facing glaciers (r2 < 0). The inclusion of a solar radiation index increased the modeled melt from the north-facing glaciers and thus improved the results (r2 = 0.73) for the north-facing glaciers, with little change from the south-facing glaciers. Including a wind index did not improve the correlation between modeled and measured runoff.

scholarly journals A digital archive of human activity in the McMurdo Dry Valleys, Antarctica

2020 ◽  
Vol 12 (2) ◽  
pp. 1117-1122
Author(s):  
Adrian Howkins ◽  
Stephen M. Chignell ◽  
Poppie Gullett ◽  
Andrew G. Fountain ◽  
Melissa Brett ◽  
...  
Keyword(s):  
Human Activity ◽  
Environmental Data ◽  
Research Management ◽  
Mcmurdo Dry Valleys ◽  
Digital Archive ◽  
Dry Valleys ◽  
Ongoing Research ◽  
Target Field ◽  
Research Activities ◽  
Long Term Ecological Research

Abstract. Over the last half century, the McMurdo Dry Valleys (MDV) of East Antarctica have become a globally important site for scientific research and environmental monitoring. Historical data can make important contributions to current research activities and environmental management in Antarctica but tend to be widely scattered and difficult to access. We address this need in the MDV by compiling over 5000 historical photographs, sketches, maps, oral interviews, publications, and other archival resources into an online digital archive. The data have been digitized and georeferenced using a standardized metadata structure, which enables intuitive searches and data discovery via an online interface. The ultimate aim of the archive is to create as comprehensive as possible a record of human activity in the MDV to support ongoing research, management, and conservation efforts. This is a valuable tool for scientists seeking to understand the dynamics of change in lakes, glaciers, and other physical systems, as well as humanistic inquiry into the history of the Southern Continent. In addition to providing benchmarks for understanding change over time, the data can help target field sampling for studies working under the assumption of a pristine landscape by enabling researchers to identify the date and extent of past human activities. The full database is accessible via a web browser-based interface hosted by the McMurdo Long Term Ecological Research site: http://mcmurdohistory.lternet.edu/ (last access: 5 May 2020). The complete metadata data for all resources in the database are also available at the Environmental Data Initiative: https://doi.org/10.6073/pasta/6744cb28a544fda827805db123d36557 (Howkins et al., 2019).

scholarly journals Patterns of bacterial biodiversity in the glacial meltwater streams of the McMurdo Dry Valleys, Antarctica

2016 ◽  
Vol 92 (10) ◽  
pp. fiw148 ◽  
Author(s):  
David J. Van Horn ◽  
Caitlin R. Wolf ◽  
Daniel R. Colman ◽  
Xiaoben Jiang ◽  
Tyler J. Kohler ◽  
...  
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Glacial Meltwater ◽  
Bacterial Biodiversity

scholarly journals An englacial hydrologic system of brine within a cold glacier: Blood Falls, McMurdo Dry Valleys, Antarctica

2017 ◽  
Vol 63 (239) ◽  
pp. 387-400 ◽  
Author(s):  
JESSICA A. BADGELEY ◽  
ERIN C. PETTIT ◽  
CHRISTINA G. CARR ◽  
SLAWEK TULACZYK ◽  
JILL A. MIKUCKI ◽  
...  
Keyword(s):  
Latent Heat ◽  
Flow Direction ◽  
Salt Content ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Outlet Glacier ◽  
Air Temperatures ◽  
Radio Echo Sounding ◽  
Hydrologic System ◽  
Taylor Glacier

ABSTRACTTaylor Glacier hosts an active englacial hydrologic system that feeds Blood Falls, a supraglacial outflow of iron-rich subglacial brine at the terminus, despite mean annual air temperatures of −17°C and limited surface melt. Taylor Glacier is an outlet glacier of the East Antarctic ice sheet that terminates in Lake Bonney, McMurdo Dry Valleys. To image and map the brine feeding Blood Falls, we used radio echo sounding to delineate a subhorizontal zone of englacial brine upstream from Blood Falls and elongated in the ice flow direction. We estimate volumetric brine content in excess of 13% within 2 m of the central axis of this zone, and likely much higher at its center. Brine content decreases, but remains detectable, up to 45 m away along some transects. Hence, we infer a network of subparallel basal crevasses allowing injection of pressurized subglacial brine into the ice. Subglacial brine is routed towards Blood Falls by hydraulic potential gradients associated with deeply incised supraglacial valleys. The brine remains liquid within the subglacial and englacial environments through latent heat of freezing coupled with elevated salt content. Our findings suggest that cold glaciers could support freshwater hydrologic systems through localized warming by latent heat alone.

scholarly journals The geochemistry of upland ponds, Taylor Valley, Antarctica

2011 ◽  
Vol 24 (1) ◽  
pp. 3-14 ◽  
Author(s):  
W. Berry Lyons ◽  
Kathleen A. Welch ◽  
Christopher B. Gardner ◽  
Chris Jaros ◽  
Daryl L. Moorhead ◽  
...  
Keyword(s):  
Chemical Weathering ◽  
Dilution Effect ◽  
Climatic Conditions ◽  
Water Bodies ◽  
Primary Control ◽  
Dry Valleys ◽  
Stream Channels ◽  
Taylor Valley ◽  
Free Region ◽  
The Impact

AbstractThe McMurdo Dry Valleys of Antarctica are the largest ice-free region on the continent. These valleys contain numerous water bodies that receive seasonal melt from glaciers. For forty years, research emphasis has been placed on the larger water bodies, the permanent ice-covered lakes. We present results from the first study describing the geochemistry of ponds in the higher elevations of Taylor Valley. Unlike the lakes at lower elevations, the landscape on which these ponds lie is among the oldest in Taylor Valley. These upland ponds wax and wane in size depending on the local climatic conditions, and their ionic concentrations and isotopic composition vary annually depending on the amount of meltwater generated and their hydrologic connectivity. This study evaluates the impact of changes in summer climate on the chemistry of these ponds. Although pond chemistry reflects the initial meltwater chemistry, dissolution and chemical weathering within the stream channels, and possibly permafrost fluid input, the primary control is the dilution effect of glacier melt during warmer summers. These processes lead to differences in solute concentrations and ionic ratios between ponds, despite their nearby proximity. The change in size of these ponds over time has important consequences on their geochemical behaviour and potential to provide water and solutes to the subsurface.

scholarly journals A digital archive of human activity in the McMurdo Dry Valleys, Antarctica

2020 ◽  
Author(s):  
Adrian Howkins ◽  
Stephen M. Chignell ◽  
Poppie Gullett ◽  
Andrew G. Fountain ◽  
Melissa Brett ◽  
...  
Keyword(s):  
Human Activity ◽  
Environmental Data ◽  
Research Management ◽  
Mcmurdo Dry Valleys ◽  
Digital Archive ◽  
Dry Valleys ◽  
Ongoing Research ◽  
Target Field ◽  
Research Activities ◽  
Long Term Ecological Research

Abstract. Over the last half century, the McMurdo Dry Valleys (MDV) of East Antarctica have become a globally important site for scientific research and environmental monitoring. Historical data can make important contributions to current research activities and environmental management in Antarctica, but tend to be widely scattered and difficult to access. We address this need in the MDV by compiling over 5,000 historical photographs, sketches, maps, oral interviews, publications, and other archival resources into an online digital archive. The data have been digitized and georeferenced using a standardized metadata structure, which enables intuitive searches and data discovery via an online interface. The ultimate aim of the archive is to create as comprehensive as possible a record of human activity in the MDV to support ongoing research, management, and conservation efforts. This is a valuable tool for scientists seeking to understand the dynamics of change in lakes, glaciers, and other physical systems, as well as humanistic inquiry into the history of the Southern Continent. In addition to providing benchmarks for understanding change over time, the data can help target field sampling for studies working under the assumption of a pristine landscape by enabling researchers to identify the date and extent of past human activities. The full database is accessible via a web browser-based interface hosted by the McMurdo Long Term Ecological Research site: http://mcmurdohistory.lternet.edu/ and the raw data are available at the Environmental Data Initiative https://doi.org/10.6073/pasta/6744cb28a544fda827805db123d36557 (Howkins et al., 2019).

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