GREENLAND’S icy mountains will not be an apparent place to seek for an archive of financial historical past, however a research simply printed within the Proceedings of the Nationwide Academy of Sciences reveals that they supply one. Joseph McConnell of the Desert Analysis Institute, in Reno, Nevada, and his colleagues have tracked financial exercise in Europe and the Mediterranean over the centuries by measuring variations within the quantity of lead in a core of Greenlandic ice. Lead is an efficient proxy for financial exercise as a result of it’s a by-product of silvermaking (lead and silver typically happen in the identical ore, often known as galena), and due to this fact of the cash provide. Extracting silver from galena entails boiling off the lead. Winds from Europe carried to Greenland sufficient lead air pollution from this course of for it to be preserved within the layers of snow that, compacted, kind the island’s ice cap.
Though the lead focus within the core that Dr McConnell checked out reveals many peaks and troughs, some…Proceed studying