Stream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica

TitleStream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica
Publication TypeJournal Article
Year of Publication2016
AuthorsGooseff, MN, Van Horn, DJ, Sudman, Z, McKnight, DM, Welch, KA, W Lyons, B
JournalBiogeosciences
Volume13
Issue6
Pagination1723 - 1732
Date Published03/2016
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.

URLhttp://www.biogeosciences.net/13/1723/2016/bg-13-1723-2016.pdf
DOI10.5194/bg-13-1723-2016
Short TitleBiogeosciences