Chemical analysis of ice vein microenvironments:II. Analysis of glacial samples from Greenland and Antarctica

• Main Authors: Barletta, Robert E, Priscu, John C, Mader, Heidy M, Jones, WL, Jones, CH
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: MCMURDO DRY VALLEYS; LAKE VOSTOK; POLAR ICE; POLYCRYSTALLINE ICE; SOLUBLE IMPURITIES; MICROBIAL HABITAT; SNOWBALL EARTH; SULFURIC-ACID; CORE; SYSTEM; Antarctic; Dominion Range; Greenland; Lake Vostok; McMurdo Dry Valleys; Newall; Newall Glacier; Antarc*; Antarctica; Antarctica Journal; glacier; Greenland Ice Sheet Project; Ice Sheet; Journal of Glaciology
• Online Access: https://hdl.handle.net/1983/a41935e3-8001-456e-89b8-4f6a1b47172c; https://research-information.bris.ac.uk/en/publications/a41935e3-8001-456e-89b8-4f6a1b47172c; https://doi.org/10.2189/2012JoG12J112

Chemical constituents trapped within glacial ice provide a unique record of climate, as well as repositories for biological material such as pollen grains, fungal spores, viruses, bacteria and dissolved organic carbon. Past research suggests that the veins of polycrystalline ice may provide a liquid microenvironment for active microbial metabolism fueled by concentrated impurities in the veins. Despite these claims, no direct measurements of impurity concentration in ice veins have been made. Using micro-Raman spectroscopy, we show that sulfate and nitrate concentrations in the veins of glacial ice from Greenland (Greenland Ice Sheet Project 2) and Antarctic (Newall Glacier and a Dominion Range glacier) core samples were 10(4) and 10(5) times greater than the concentrations measured in melted (bulk) core water. Methanesulfonate was not found in the veins, consistent with its presence as particulate matter within the ice. The measured vein concentration of molecular anions implies a highly acidic (pH <3) vein environment with high ionic strength (mM-M). We estimate that the vein volume provides 16.7 and 576 km(3) of habitable space within the Greenland and Antarctic ice sheets, respectively, which could support the metabolism of organisms that are capable of growing in cold, high ionic strength solutions with low pH.