DEPOSITION OF ATMOSPHERIC HEAVY-METALS TO THE GREENLAND ICE-SHEET FROM THE 1783-1784 VOLCANIC-ERUPTION OF LAKI, ICELAND

In order to assess better the influence of major volcanic events on th e large scale atmospheric cycles of heavy metals, Greenland ice dated from the time of the fallouts from the great 1783-1784 eruption of Lak i volcano in Iceland has been analysed for Pb, Cd, Cu, Zn and sulphate . The concentrations of the four heavy metals investigated are found t o be greatly enhanced in the ice layers which correspond to the fallou ts from the eruption, confirming that such events do modify the a atmo spheric cycles of heavy metals, Cumulative fallout of heavy metals to the whole Greenland ice cap from the 1783-1784 Laki eruption ranges fr om 1 t for Pb and Cd to 40 t for Zn. For Cd, Cu and Zn, it represents a few percent of the cumulative anthropogenic fallout to the ice cap f rom the Industrial Revolution to the present,