Greenland ice sheet releasing "Mississippi River” worth of phosphorus

Not only is Greenland's melting ice sheet adding huge amounts of water to the oceans, it could also be unleashing 400,000 metric tons of phosphorus every year - as much as the mighty Mississippi River releases into the Gulf of Mexico, according to a new study. Phosphorus is a key nutrient that could, if it reaches the open ocean, enrich waters of the Arctic Ocean, potentially stimulating growth of the marine food chain. Phosphorus feeds plankton at the base of the ocean food web. Glacial meltwater has long been known to contain phosphorus, but new research by Dr Jon Hawkings, from the Cabot Institute at the University of Bristol, shows as the Greenland ice sheet melts, it could be releasing far more of the nutrient than previously thought. Dr Hawkings and his collaborators spent three months in 2012 and 2013 gathering water samples and measuring the flow of water from the 600-square-kilometer (230-square-mile) Leverett Glacier, and the smaller, 36-square-kilometer (14-square-mile) Kiattuut Sermiat Glacier in Greenland, as part of a Natural Environment Research Council-funded project to understand how much phosphorus, in its various forms, was escaping from the ice sheet over time and draining into the sea. They used that data to extrapolate how much phosphorus was likely being released from the entire Greenland ice sheet. 'We found greater amounts of phosphorus in the waters of the Leverett Glacier than had been detected at previous study sites, which have looked mostly at smaller glaciers.