Have we taken Earth's pulse?

摘要

Earth may have a heartbeat. Evidence from Hawaii and Iceland hints that the planet's core may be dispatching simultaneous plumes of magma towards the surface every 15 million years or so.rnIf the hypothesis is true, it would revolutionise our ideas of what's happening far below our feet. Independent scientists contacted by New Scientist were split, with some scornful and others intrigued.rnRolf Mjelde of the University of Bergen and Jan Inge Faleide of the University of Oslo, both in Norway, used seismological data to measure the thickness of Earth's crust between Iceland and Greenland (see map). Iceland is on the Mid-Atlantic Ridge, where magma wells up to form fresh crust.