Magma could be moving in the crust beneath the West Antarctic Ice Sheet, reports a study published online this week in Nature Geoscience. Several volcanoes are known to exist in West Antarctica, but none were thought to be active at present.
Amanda Lough and colleagues analysed seismic data from a highland range in West Antarctica. They identified two earthquake swarms, one in 2010 and the other in 2011, occurring at depths of about 25 to 40 km below the West Antarctic Ice Sheet. The earthquake swarms exhibited characteristics typical of earthquakes that occur beneath active volcanoes, and that are generated by magma moving in the crust. Although an eruption at this site would be unlikely to penetrate the thick overlying ice, heat flow from an eruption could melt the base of the ice sheet.
In an accompanying News and Views article, John Behrendt says: “This process could potentially lubricate the ice-sheet bed, help the overlying ice to flow, and facilitate the evolution of ice streams. All these processes could lead to accelerating ice mass loss in West Antarctica.”