CGRG Bibliography of Canadian Geomorphology
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Author : Barker, J.; and Sharp, M.
Date : 2005.
Title : The distribution of anions beneath two polar glaciers.
Publication : 35th Annual International Arctic Workshop. March 9-12, 2005. Timms Centre for the Arts, University of Alberta, Edmonton, Alberta, Canada.
Issue :
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Abstract
Glaciers overrun sediment and organic carbon (OC) in soils and vegetation during periods of advance. Glacier basal ice formation can result in the incorporation of this overrun sediment and OC into the glacier ice mass. Recent investigations reporting the existence of viable microbial populations that were cultured from basal ice samples raises the possibilities that 1) active microbial metabolism occurs within the glacier ice matrix, 2) microbes in basal ice can use overrun sediment and OC during metabolism. Evidence of microbial metabolic activity within basal ice could be reflected by the ionic composition of basal ice samples. This investigation reports the concentration and distribution of five organic anions (acetate, formate, methylsulphonic acid (MSA), oxalate) and five inorganic anions (chloride, fluoride, nitrate, nitrite, sulphate) in basal ice that was sampled across the basal ice/meteorically-derived ice interface in two polar glaciers which are characterized by different potential nutrient sources. John Evans Glacier is a polythermal glacier that overlies carbonate sediment in a polar desert ecosystem in arctic Canada. Victoria Upper Glacier is a cold based glacier that overlies weathered silicate sediment and is adjacent to an ice covered lake (potential source of algal OC) in the McMurdo Dry Valleys of Antarctica. The results of this investigation indicate that 1) the mechanisms for basal ice formation exerts an influence on the distribution of anions within the basal ice sequence, 2) while the characteristics of the source OC and overrun geological material exert an influence on the anions present in basal ice, englacial and/or subglacial biogeochemical processes modify its anion composition, 3) the distribution of anions within basal ice is spatially heterogeneous as the result of these processes.
Bibliography of Canadian Geomorphology