New layer of molten rock identified ‘hidden’ under the Earth’s tectonic plates - Express

Scientists have identified a previously unknown layer of partially molten rock hidden below the Earth’s crust — one that may help settle a long-standing puzzle about how tectonic plates move.

Intrigued by signs of partially molten rock under the crust in these images, he began to compile similar data from around the world, until he had put together essentially a global map of the asthenosphere.

The molten layer sits around 100 miles beneath the surface and is part of the asthenosphere (Image: Junlin Hua / UT Jackson School of Geosciences)This “map” revealed that such molten rock was commonplace, encompassing almost half of the Earth and appearing on the seismic readings wherever the asthenosphere was hottest — and not, as had been previously assumed, just a series of localised anomalies.

Instead, Dr Hua and colleagues found, the principal influence on the motion of Earth’s tectonic plates appears instead to be the convention of heat and rock in the mantle.

Demonstrating that the newly-identified melt layer has no influence on plate tectonics means one less thing to worry about when creating models of the Earth, the team said.

There is much to still learn about the Earth's interior (Image: Express.co.uk)Paper co-author and geodynamicist Professor Thorsten Becker commented: “We can’t rule out that, locally, melt doesn’t matter.