The chemistry of cryoconite holes on Canada glacier was measured in January, 2001 at seven locations. Water analysis was conducted for pH, electrical conductivity and a nematodes census.
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The Canada glacier was sampled for cryoconite holes over a period of three days by Thomas Nylen, Robin Johnston and Dorota Porazinska. Samples 1-12 were collected in the evening of 16 January 2001, samples 13-38 throughout the entire day of 17 January 2001, and the remaining sampl es throughout the entire day of 18 January 2001.Samples were taken from seven different locations on the Canada Glacier. GPS coordinates of these sites and the number of samp les taken at each site is the following:
At each location, cryoholes adjacent to each other were sampled. All cryoholes (except one) were frozen solid. To reach the sediment layer, a Sipre ice corer was used. As soon as a cryohole was located, the diameter in N-S and E-W directions was recorded, and followed by drilling into the ice until the sediments would show up in the drilling dust accumulating on the ice surface. All drilling was done by Thomas Nylen. When the ice core was excavated, the depth of the cryohole (from the ice surface to bottom of the sediment layer), and the width of the sediment layer were measured. Only 25 cm (from the bottom of the sediment up) of the ice core were packed into sterile Whirl-Pak large plastic bags, stored in a back pack and brought down to the Lake Hoare camp lab. The Sipre ice corer and other heavy supplies were pulled on sleds. All ice cores were left in the lab at room temperature conditions to melt. Since plastic bags can be perforated by the sharpness of ice cores, bags containing ice cores were placed in plastic beakers to prevent leakage. Ice cores melted within 16 hours. When melted, samples were shaken to mix the sediment and water and left for at least 5 hours for the sediment to settle. 300 ml of supernatant were transferred into 500 ml Nalgene bottles (washed in soap water and rinsed three times with DI water). 100 ml of this volume were filtered on a column tower using 47mm 0.4micro PC membrane filters and collected into 100ml Nalgene bottles (washed as above) and used for cation and anion concentrations. Additional 100ml was filtered through baked 47mm Whatman GF/F filters and collected into 100ml amber glass bottles (washed as above, and baked at 470degC capped with aluminum foil, then closed with original caps that were rinsed in 10% HCL and DI water) for DOC. To kill all possible organisms in the water samples and thus prevent usage of DOC, samples were fixed with 1 ml of 37% HCL ( added to the bottles right after filtration). Filtration was done by Dorota Porazinska. The remaining water with sediment was transferred from the Whirl-Pak bags into 500ml Nalgene bottles. All samples were packed into coolers and transported back to McMurdo lab on 20 January 2001 where they were processed for pH, EC, and nematodes using standard protocols. [DP 20 Jan 01].
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