WHY WOULD a meteorologist concern herself with the rocks beneath her feet? For good reason, if she lives in Iceland. That island nation straddles the mid-Atlantic ridge, a boundary between two of Earth’s crustal plates which are drifting apart. That allows hot, liquid rock called magma to well up from the depths. Iceland also sits just below the Arctic circle and enjoys glacier-promoting temperatures. As a consequence of these facts, it is home to 34 active volcanoes, half of which are buried under ice up to 1km thick. And that ice is melting as the climate warms.