Monday, May 9, 2016

Science & Technology: Mantle Heat Convection is Bigger than Previously Thought

We Were Totally Wrong About What's Happening Inside Earth's Mantle (Gizmodo)

For the first time, geologists have compiled a global map of the wave-like motions called “convective currents” inside Earth’s mantle. They found that those convective currents are moving roughly ten times faster than previously thought. The discovery can help explain everything from how Earth’s surface changes over time to the formation of fossil fuel deposits to long-term climate change.

“In geological terms, the Earth’s surface bobs up and down like a yo-yo,” geologist Mark Hoggard of Cambridge University said in a statement. Hoggard is lead author on a paper published today in Nature Geoscience.

Our planet’s deep interior is an enduring scientific mystery. Having never drilled more than a few miles beneath the surface of the Earth, geologists rely on indirect measurements and models to get a sense of what’s happening further down. The mantle is a nearly 3000 kilometer (2000 mile) layer of gooey, compressed rock, and convective activity within it has a big impact on Earth’s surface.