Antarctic Science

Research Article

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

Kathleen A. Welcha1 c1, W. Berry Lyonsa1, Carla Whisnera1, Christopher B. Gardnera1, Michael N. Gooseffa2, Diane M. McKnighta3 and John C. Priscua4

a1 The Ohio State University, Byrd Polar Research Center, 1090 Carmack Rd, 108 Scott Hall, Columbus, OH 43210, USA

a2 Department of Civil and Environmental Engineering, Pennsylvania State University, University Park, PA 16802, USA

a3 University of Colorado, INSTAAR, Boulder, CO 80309-0450, USA

a4 Dept LRES, 334 Leon Johnson Hall, Montana State University, Bozeman, MT 59717, USA

Abstract

Streams 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.

(Received April 02 2010)

(Accepted August 08 2010)

Correspondence:

c1 welch.189@osu.edu

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