Identifying the Predominant Sources of Atmospheric Dust to the Antarctic using Peat Cores from Ombrotrophic Sphagnum Bogs in Patagonia
Professor Dr. William Shotyk
University of Alberta
Department of Renewable Resources
Antarctic ice cores document considerable variation in the fluxes of atmospheric soil dust, volcanic ash particles, and trace metals, but the records are incomplete and the predominant sources of these aerosols are poorly characterised with respect to space and time. Ombrotrophic peat bogs are excellent archives of most atmospheric particles and a wide range of trace metals, and are abundant in Tasmania, New Zealand and Patagonia. The study proposed here will represent the first complete, long term (13.000 yr), high resolution reconstruction of atmospheric dust and trace metal deposition for the southern hemisphere. Conservative, lithogenic trace metals (Ti, Y, Zr, Hf, REE) will be used to quantify the changing rates of atmospheric soil dust deposition, and the ration of these elements to Sc will document changes in mineralogy and particle size. Lead and Sr isotope data will be used to identify changes in predominant dust source areas which will provide new insight into Holocene climate change in the southern hemisphere. Arsenic, Ag, Cd, Sb and Pb will be used to estimate anthropogenic contributions to the metal fluxes. In addition, trace elements supplied by volcanoes will be identified using changes in Au and Bi concentrations, and cosmogenic dust using Os and Ir. These new terrestrial records will complement the existing trace metal and dust records from Antarctica snow and ice archives, and fill in a number of important research gaps.
term from 2003 to 2008