Continents do not just break apart at the surface -- they also peel away from below, feeding volcanic activity in the oceans, according to a study published Tuesday in Nature Geoscience.
Researchers found that fragments of continental material are slowly stripped from underneath the landmass and carried into the oceanic mantle -- the hot, mostly solid layer beneath the seafloor that circulates over time.
Computer simulations showed that as tectonic forces stretch Earth's crust, they trigger a slow "mantle wave" deep below the continents. This rolling motion, occurring 150 to 200 kilometers beneath the surface, gradually removes pieces of the continents' deep roots.
Over tens of millions of years, these fragments travel more than 1,000 kilometers sideways into the oceanic mantle, where they continue to fuel volcanic eruptions.
The research team supported its model by analyzing chemical and geological signatures from volcanic formations in the Indian Ocean linked to the breakup of the ancient supercontinent Gondwana more than 100 million years ago.
