Earth’s Core is Cooling Faster than Expected, Researchers Say

According to a new research, the Earth's core is cooling much faster. That could change our fundamental understanding of the evolution of the Earth.

To get an idea of ​​how far Earth is in this process, scientists are studying the thermal conductivity of minerals in the layers between the core and the mantle.

In other words, the heat from the core is being passed on at a much faster rate than previously thought, leading to the greater cooling of the Earth.

In a lab simulation, a team of researchers from ETH Zurich and the Carnegie Institution for Science in Switzerland applied immense amounts of pressure and heat to a mineral called bridgmannite.

This pressure and temperature were roughly the same as those found in the transitional zone between the core and the mantle—to simulate conditions—deep beneath the surface.

Then, researchers measured earth's thermal conductivity to get a better understanding of the cooling processes at play. The result were surprising.

"This measurement system shows us that the thermal conductivity of 'bridgmanite' is 1.5 times higher than estimated", said ETH Professor Motohiko Murakami, lead author of a paper about the findings published in the journal Earth and Planetary Science.

In other words, heat is being passed through the planet's core at a much faster rate than previously estimated, causing Earth to cool more and more.

The study could rewrite what we already know about the dynamical processes leading to the slowing of convection currents.

"Our results may provide us with a new perspective on the evolution of Earth's dynamics" Murakami explained. "They suggest that Earth, like the other rocky planets Mercury and Mars, is cooling and deactivating much faster than expected."

However, the researcher noted that we didn't know enough to determine how long it would take for the convection currents to stop completely.

Once the Earth's core cools down, the planet will lose its magnetic shield, which protects the surface from harmful solar radiation. 

Without the shield, life on Earth will die out, turning the planet into a lifeless rock. Scientists estimate that won't happen for another 1.75 to 3.25 billion years.