Magma surge the size of Los Angeles builds under Yellowstone: “The remains of the Yellowstone supervolcano in the US is huffing and puffing and rising by up to 7 centimetres a year, say researchers… But the researchers, led by Wu-Lung Chang of the University of Utah in the US, caution that the movement does not mean an explosion is imminent. Calderas – the massive craters that are left behind when a volcano collapses – all over the world go up and down over decades.”