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 the large scale atmospheric cycles of heavy metals, Greenland ice dated from the time of the fallouts from the great 1783–1784 eruption of Laki volcano in Iceland has been analysed for Pb, Cd, Cu, Zn and sulphate. The concentrations of the four heavy metals investigated are found to be greatly enhanced in the ice layers which correspond to the fallouts from the eruption, confirming that such events do modify the atmospheric cycles of heavy metals. Cumulative fallout of heavy metals to the whole Greenland ice cap from the 1783–1784 Laki eruption ranges from 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 from the Industrial Revolution to the present.