A Huge Subterranean ‘Tree’ Is Moving Magma to Earth’s Surface

RÉUNION, A FRENCH island in the western Indian Ocean, is like a marshmallow hovering above the business end of a blowtorch. It sits above one of Earth’s mantle plumes—a tower of superheated rock that ascends from the deep mantle and flambées the bases of tectonic plates, the jigsaw pieces that make up the ever-changing face of the world. The plume’s effects are hard to miss: One of the island’s two massive volcanoes, the aptly named Piton de la Fournaise, or “Peak of the Furnace,” is one of the most hyperactive volcanoes on the planet. But the plume’s modern-day punch is nothing compared to its past.-- More...