Arctic lakes

• Main Authors: Neal Michelutti A, Antonio Simonetti B, Jason P. Briner C, Svend Funder D, Robert A. Creaser B, Er P. Wolfe B
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Baffin Island; Canada; Clyde River; Greenland; Baffin
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.580.8940; http://faculty.eas.ualberta.ca/wolfe/eprints/Michelutti_STOTEN.pdf

Sediment geochemistry Atmospheric deposition Concentrations and stable isotope ratios of lead (Pb) from lake sediments were used to quantify temporal patterns of anthropogenic Pb pollution in the Clyde River region of Baffin Island, Arctic Canada. Surface sediments from eight lakes on eastern Baffin Island and one from northern-most Greenland, spanning a gradient of 20 ° latitude, showed great variability with respect to Pb concentration and stable isotopic Pb ratios, with little apparent latitudinal trend. To constrain the temporal evolution of regional Pb pollution, a well-dated core from one of the sites, Lake CF8 on east-central Baffin Island, was analyzed geochemically at high stratigraphic resolution. A pronounced decrease in the 206Pb/207Pb ratio occurs in sediments deposited between 1923 and the mid-1970s, likely reflecting alkyl-Pb additives derived from the combustion of fossil fuels at a global scale. A two-component mixing model indicates that 17–26 % of the Pb in the labile fraction of sediments deposited in Lake CF8 between 2001 and 2005 is from anthropogenic input. A Pb–Pb co-isotopic plot (206Pb/207Pb vs. 208Pb/206Pb ratios) of the Lake CF8 time series data indicates multiple possible sources of industrial Pb pollution. Despite widespread reductions in industrial Pb emissions since the 1970s, there is no evidence for attendant reductions of pollution Pb at Lake CF8. Enhanced scavenging from increased