Geologists discover tectonic plate’s slippery underbelly | Science News

ADVERTISEMENT

REAL SCIENCE. REAL NEWS.

Help us keep you informed.

Support Science News.


News

Geologists discover tectonic plate’s slippery underbelly

Dynamite blasts divulge runny layer roughly 100 kilometers below surface

By
1:00pm, February 4, 2015
Tectonic plate diagram

SLIP ‘N SLIDE  A layer of slippery, partially melted rock (red) may separate the Pacific tectonic plate from the underlying mantle, reducing the amount of force required to shift the massive plate, new seismic research suggests.

Using ricocheted vibrations from dynamite blasts, researchers have glimpsed a layer of gooey material sandwiched between the Pacific tectonic plate and the underlying mantle. If present beneath all plates, the layer of partially melted rock could help explain how tectonic plates slide around Earth’s surface so easily, the researchers report in the Feb. 5 Nature.

“A weak, slippery base essentially decouples the plate from the sticky, underlying mantle,” says lead author Tim Stern, a geophysicist at Victoria University of Wellington in New Zealand. “This gives us a good idea about the forces required to push and pull the plates around.”

Earth’s outermost shell is a fragmented jigsaw puzzle of rocky plates sliding over the mantle below. The bottoms of these plates can be hundreds of kilometers underground, making them much too thick to drill through. Geophysicists

This article is only available to Science News subscribers. Already a subscriber? Log in now. Or subscribe today for full access.

Get Science News headlines by e-mail.

More from Science News

From the Nature Index Paid Content