@article {4845, title = {Spatial patterns of major ions and their relationship to sediment concentration in near surface glacier ice, Taylor Valley Antarctica}, journal = {Journal of Geophysical Research: Earth Surface}, year = {2023}, month = {03/2024}, abstract = {

Glaciers form the headwaters of many watersheds and, in arid polar environments, can provide the vast majority of water to downstream systems. Headwater watersheds are critically important for setting the chemistry for downstream systems, yet we know comparatively little about the patterns and processes that generate the geochemical signature of meltwater on glacier surfaces. Here, we focus on glaciers in the McMurdo Dry Valleys of Antarctica, the largest ice-free area on the continent, characterized by alpine glaciers flowing into broad, rocky valleys. We examine patterns from the coast inland, accumulation to ablation zones, laterally across individual glaciers, and through the zone of meltwater generation. We directly compare solute to sediment concentrations, a major source of dissolved solutes. Our findings agree with previous work that the overall meltwater chemistry of a given glacier is a product local sediment sources and of regional wind patterns: foehn winds moving from the ice sheet to the coast and on-shore sea breezes. Further, these patterns hold across an individual glacier. Finally, we find that the ice chemistry and sediment profiles reflect freeze-thaw and melt processes that occur at depth. This indicates that the transport and weathering of sediment in the ice profile likely has a strong influence on supra- and proglacial stream chemistry. This new understanding strengthens connections between physical and geochemical processes in cold-based polar glacier environments and helps us better understand the processes driving landscape and ecosystem connectivity.

}, keywords = {LTER-MCM}, issn = {2169-9003}, doi = {10.1029/2022JF006980}, url = {https://onlinelibrary.wiley.com/doi/10.1029/2022JF006980}, author = {Bergstrom, Anna J. and Kathleen A. Welch and Michael N. Gooseff} } @article {3875, title = {Stream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica}, journal = {Biogeosciences}, volume = {13}, year = {2016}, month = {03/2016}, pages = {1723 - 1732}, 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.

}, keywords = {LTER-MCM}, doi = {10.5194/bg-13-1723-2016}, url = {http://www.biogeosciences.net/13/1723/2016/bg-13-1723-2016.pdf}, author = {Michael N. Gooseff and David J. Van Horn and Sudman, Zachary and Diane M. McKnight and Kathleen A. Welch and W. Berry Lyons} } @article {1154, title = {Spatial variations in the geochemistry of glacial meltwater streams in the Taylor Valley, Antarctica}, journal = {Antarctic Science}, volume = {22}, year = {2010}, month = {12/2010}, pages = {662 - 672}, keywords = {LTER-MCM}, doi = {10.1017/S0954102010000702}, url = {http://www.montana.edu/lkbonney/DOCS/Publications/WelchEtAl2010Geochemistry.pdf}, author = {Kathleen A. Welch and W. Berry Lyons and Whisner, Carla and Christopher B. Gardner and Michael N. Gooseff and Diane M. McKnight and John C. Priscu} } @article {1223, title = {SPME-GCMS study of the natural attenuation of aviation diesel spilled on the perennial ice cover of Lake Fryxell, Antarctica}, journal = {Science of the Total Environment}, volume = {407}, year = {2008}, pages = {250-262}, keywords = {LTER-MCM}, author = {Jaraula, C and Kenig, Fabien and Peter T. Doran and John C. Priscu and Kathleen A. Welch} } @article {1237, title = {Solute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica}, journal = {Geological Society of America Bulletin}, volume = {119}, year = {2007}, month = {01/2007}, pages = {548-555}, keywords = {LTER-MCM, Climate Response}, doi = {10.1130/B25913.1}, url = {http://gsabulletin.gsapubs.org/content/119/5-6/548.short}, author = {Harris, K and Anne E. Carey and Kathleen A. Welch and W. Berry Lyons and Andrew G Fountain} } @article {1368, title = {Strontium isotopic signatures of the streams and lakes of Taylor Valley, southern Victoria Land, Antarctica: chemical weathering in a polar climate}, journal = {Aquatic Geochemistry}, volume = {8}, year = {2003}, pages = {875-895}, keywords = {LTER-MCM}, author = {W. Berry Lyons and C. A. Nezat and Benson, L and Bullen, T and Graham, E and Kidd, J and Kathleen A. Welch and Thomas, J} } @article {1369, title = {Surface glaciochemistry of Taylor Valley, southern Victoria Land, Antarctica and its relationship to stream chemistry.}, journal = {Hydrological Processes}, volume = {17}, year = {2003}, pages = {115-130}, keywords = {LTER-MCM}, author = {W. Berry Lyons and Kathleen A. Welch and Andrew G Fountain and Gayle L. Dana and Bruce H. Vaughn and Diane M. McKnight} }