Research article
21 Mar 2016
Research article | 21 Mar 2016
Stream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica
Michael N. Gooseff1, David Van Horn2, Zachary Sudman3, Diane M. McKnight1, Kathleene A. Welch4, and William B. Lyons4
Michael N. Gooseff et al.
Michael N. Gooseff1, David Van Horn2, Zachary Sudman3, Diane M. McKnight1, Kathleene A. Welch4, and William B. Lyons4
- 1Institute of Arctic and Alpine Research, University of
Colorado, Boulder, Colorado, USA
- 2Department of Biology, University of New Mexico, Albuquerque, New Mexico,
USA
- 3Department of Civil & Environmental Engineering, Colorado State University, Fort Collins, CO, USA
- 4School of Earth Sciences, The Ohio State University, Columbus, Ohio,
USA
- 1Institute of Arctic and Alpine Research, University of
Colorado, Boulder, Colorado, USA
- 2Department of Biology, University of New Mexico, Albuquerque, New Mexico,
USA
- 3Department of Civil & Environmental Engineering, Colorado State University, Fort Collins, CO, USA
- 4School of Earth Sciences, The Ohio State University, Columbus, Ohio,
USA
Correspondence: Michael N. Gooseff (michael.gooseff@colorado.edu)
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Received: 30 Jun 2015 – Discussion started: 08 Sep 2015 – Revised: 03 Feb 2016 – Accepted: 17 Feb 2016 – Published: 21 Mar 2016
Abstract. Stream channels in the McMurdo Dry Valleys are characteristically wide, incised, and stable. At typical flows, streams occupy a fraction of the oversized channels, providing habitat for algal mats. In January 2012, we discovered substantial channel erosion and subsurface thermomechanical erosion undercutting banks of the Crescent Stream. We sampled stream water along the impacted reach and compared concentrations of solutes to the long-term data from this stream ( ∼ 20 years of monitoring). Thermokarst-impacted stream water demonstrated higher electrical conductivity, and concentrations of chloride, sulfate, sodium, and nitrate than the long-term medians. These results suggest that this mode of lateral permafrost degradation may substantially impact stream solute loads and potentially fertilize stream and lake ecosystems. The potential for sediment to scour or bury stream algal mats is yet to be determined, though it may offset impacts of associated increased nutrient loads to streams.
