MANTLE DYNAMICS:
Iceland's Fires Tap the Heart of the Planet
Richard A. Kerr
Many researchers have thought that mantle plumes--narrow columns of rising hot rock that feed volcanoes at hot spots like Hawaii and Iceland--tap the deep mantle, but they had no hard evidence, and others argued that plumes have shallower roots. Now, by using new tricks to process earthquake waves into a seismic image, two seismologists have produced an image of a plume rising from near the bottom of the mantle, 2900 kilometers down, all the way up to Iceland's surface, as they report in a recent issue of Earth and Planetary Science Letters.