Privileged Planet: new seismic findings (Introduction)

by David Turell , Wednesday, January 05, 2022, 15:27 (840 days ago) @ David Turell

Ultra-low velocity zones control plate tectonics which are required for life to appear:

https://www.sciencealert.com/possible-chemical-leftovers-from-earth-s-birth-are-still-l...

"Chemical leftovers from the very earliest days of our planet could still be present near Earth's core, according to new research, and the discovery could improve our understanding of plate tectonics phenomena happening today.

"The team behind the study compares these leftovers to clumps of flour at the bottom of a bowl of batter – elements that haven't been properly mixed over the course of billions of years, which show up as anomalies on seismic wave readings.

"We know that seismic waves slow to a crawl near the core of the Earth, going through what are known as ultra-low velocity zones (ULVZs). The big question is what are these zones made out of – and scientists now think they might have found the answer.

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"'We found that this type of ultra-low velocity zone can be explained by chemical heterogeneities created at the very beginning of the Earth's history and that they are still not well mixed after 4.5 billion years of mantle convection."

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"The mantle and the ULVZs at the bottom of it can drive the movement of tectonic plates close to the surface, which means the new research doesn't just teach us more about the birth of the Earth, but also more about how it's behaving today.

"'Of all of the features we know about in the deep mantle, ultra-low velocity zones represent what are probably the most extreme," says geologist Michael Thorne from the University of Utah.

"'Indeed, these are some of the most extreme features found anywhere in the planet.'"

Comment: We know the Earth is very special and this is another evidence of its design for life.