Earth’s mantle is cooling faster than expected
Thickness of newly formed mid-ocean ridge crust varies depending on interior heat
COOLING DOWN Newly formed oceanic crust (redder shaded regions) is thinner on average than older crust, new research shows. This thinning suggests that Earth’s mantle is cooling faster than previously thought.
NCEI/NOAA; R.D. Müller et al/Geochem. Geophys. Geosyst. 2008
SAN FRANCISCO — Earth’s innards are cooling off surprisingly fast.
The thickness of new volcanic crust forming on the seafloor has gotten thinner over the last 170 million years. That suggests that the underlying mantle is cooling about twice as fast as previously thought, researchers reported December 13 at the American Geophysical Union’s fall meeting.
The rapid mantle cooling offers fresh insight into how plate tectonics regulates Earth’s internal temperature, said study coauthor Harm Van Avendonk, a geophysicist at the University of Texas at Austin. “We’re seeing this kind of thin oceanic crust on the seafloor that may not have existed several hundred million years ago,” he said. “We always consider that the present is the clue to the past, but that doesn’t work here.”
The finding is fascinating, though the
