Scientists seeking to understand the forces at work beneath the Earth’s surface have detected previously unknown “fingers” of heat, some of them thousands of miles long, in our planet’s upper mantle. The discovery helps explain the “hotspot volcanoes” that give birth to island chains such as Hawaii and Tahiti.
Many volcanoes arise at collision zones between the tectonic plates, but hotspot volcanoes form in the middle of the plates, researchers said.
Geologists have hypothesised that upwellings of hot, buoyant rock rise as plumes from deep within Earth’s mantle and supply the heat that feeds these mid-plate volcanoes.
Computer modelling approach, developed by University of Maryland seismologist Vedran Lekic and colleagues at University of California, has produced new seismic wave imagery which reveals that the rising plumes are influenced by a pattern of finger-like structures carrying heat deep beneath Earth’s oceanic plates.