Talk by Paul Vallelonga – Niels Bohr Institute - University of Copenhagen

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Niels Bohr Institute > Calendar > Activities 2013 > Talk by Paul Vallelonga

Talk by Paul Vallelonga

Title: Greenland 2012 snow pits and NEGIS firn core update

Summer of 2012 was an interesting time to be in Greenland. The final season of the NEEM deep ice core drilling campaign. Above-zero atmospheric temperatures across the whole of the Greenland ice sheet on the 12th of July. Glacial meltwater washed away the bridge in Kangerlussuaq, threatening access to the town water supply and closing the rowing club restaurant. During the July melt event, regular measurements of NEEM snowpack temperatures, chemistry and physical features were made, allowing a unique opportunity to study what happens in the creation of a Greenland melt layer. I will present a short summary of the conditions at NEEM and the scientific observations made.

During June of 2012, NEEM camp was also used as a staging point for the first site survey of the Northeast Greenland Ice Stream (NEGIS), located approximately 250 km east of NEEM and 200 km north of NGRIP. Radar and seismic scans were made of the area, and a 70 m shallow core was drilled. DEP and ECM measurements have allowed the identification of volcanic acid layers and hence the establishment of a preliminary timescale. In January 2013, Continuous measurements of stable water isotopes and chemical impurities in the NEGIS core were undertaken at CIC. The identification of seasonal variability in dust, sodium and ammonium concentrations allow the chronology to be refined to sub-annual resolution. I will present preliminary results obtained by the many people involved in studying the NEGIS shallow core.

P. Vallelonga represents the CIC chemistry, isotopes, stratigraphy and modelling groups and NEGIS partners (AWI & CReSIS)