J. Phys. IV France 107 (2003) 545
A 6,000-years record of atmospheric mercury accumulation in the high Arctic from peat deposits on Bathurst Island, Nunavut, CanadaN. Givelet1, F. Roos-Barraclough1, M.E. Goodsite2 and W. Shotyk3
1 Institute of Geological Sciences, University of Berne, Baltzerstrasse 1-3, 3012 Berne, Switzerland
2 Department of Chemistry, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark
3 Institute of Environmental Geochemistry, University of Heidelberg : lm Neuenheimer Feld 236, 69120 Heidelberg, Germany
There is a growing interest in the atmospheric transport, deposition, and accumulation of anthropogenic Hg in the Arctic. To quantify the impact of industrial Hg emissions, the natural rate of atmospheric Hg accumulalion must be known. Mercury concentration measilrements and age dating oi peatfrom the Canadian Arctic show that natural "background" Hg flux rather constant (ca. 1 microgram per sq. m per yr.) throughout the past 6,000 years. Mercury concentrations in surface peat layers are much higher, but chronology ofthese changes cannot be interpreted until more age dates are available. The elevated Hg concentrations in surface layers, however, are out of proportion with Br and Se, suggesting that there has been a significant human impact. Peat cores from southern Canada provide a record of atmospheric Hg accumulation extending back nine thozisand years, with similar backgroundfluxes. Thus, pre-anthropogenic Hg fluxes in the High Arctic were not significantly differentfrom atmospheric Hg fluxes in the temperate Zone.
© EDP Sciences 2003