Glaciers — giant blocks of moving ice — along Antarctica’s coastline are flowing faster in the summer because of a combination of melting snow and warmer ocean waters, say researchers. On average, the glaciers travel at around one kilometre a year. But a new study has found a seasonal variation to the speed of the ice flow, which speeded up by up to 22 % in summer when temperatures are warmer. This gives an insight into the way climate change could affect the behaviour of glaciers and the role they could play in raising sea levels.