Microbes fuelled by wind-blown mineral dust melt the Greenland ice sheet

Scientists have identified a key nutrient source used by algae living on melting ice surfaces linked to rising sea levels.The Greenland ice sheet—the second largest ice body in the world after the Antarctic ice sheet—covers almost 80% of the surface of Greenland. Over the last 25 years, surface melting and water runoff from the ice sheet has increased by about 40%.The international research team, led by the University of Leeds, analysed samples from the southwestern margin on Greenland's 1.7 million km2 ice sheet over two years.They discovered that phosphorus containing minerals may be driving ever-larger algal blooms on the Greenland Ice Sheet. As the algal blooms grow they darken the ice surface, decreasing albedo—the ability to reflect sunlight. The blooms cause increased melting thus contributing to higher sea levels. In particular, a band of low-albedo ice, known as the Dark Zone, has developed along the western margin of the massive ice sheet.

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