DECONVOLUTING MERCURY DEPOSITION PATTERNS ACROSS SPACE AND TIME

The total atmospheric contribution of mercury (Hg_T) to lake sediments can be quantified using cores acquired from the deep portions of lakes. Sediment core intervals are dated radiometrically with ²¹⁰Pb and are analyzed by various methods to determine Hg concentration values. Algorithms based on estimates of lake and watershed processes can be applied to data to more accurately assess the anthropogenic contribution of Hg to the environment (Hg_A). The calculation of Hg_A values has been the major goal of recent research in the northeast US. Application of GIS software can provide a regional platform upon which Hg_A values can be compared across time and space. Time series maps have been developed at 1850, 1900, 1950, 1975 and 1990 time slices to view the background, the transitional, and the modern Hg_A values. Incorporation of additional data points will enhance the temporal and spatial resolution of the map series. This GIS database will provide a straightforward means to present atmospheric Hg deposition information, as determined from lake cores, from across New England, the upper Midwest, and the Maritime provinces.