A 10-CENTURY COMPARISON OF PROMINENT BIPOLAR VOLCANIC EVENTS IN ICE CORES

Measurements of key chemical and physical parameters made along contin uous and selected long sections of polar ice cores provide reliable pa st snow accumulation rates and other environmental records. The prime accumulation indicators include variations found in the stable isotope s, ionic constituents, and acidity concentration levels; and physical changes in the strata and structure. Cross correlations of the time se ries curves resulting from multiparameter analyses of ice cores from A ntarctica (NBY89, SP78, BS68) and Greenland (CR74, D3 81, D3 18C) have been made. The results permit construction of a bipolar chemical stra tigraphy chronology of volcanic events that is coherent with the delta O-18 and Electrical Conductivity Method data sets and consistent back -in-time with historically recorded volcanic activity. A bihemispheric comparison of high non-sea-salt SO42- peaks shows strong correlation at 1885, 1836, 1816, 1810, 1459, 1346, 1287, 1278, 1254, 1228, and 116 8 A.D. at time of snow deposit. The prominent 1259 A.D. volcanic signa l appears to be a significant bipolar ice core index horizon.