North American Plate Once Preferred Hare To Tortoise

NASA Visible Earth

New research out of Michigan Tech suggests that we live on a tectonic plate that was once more interested in breaking land speed records than the slow and steady. MTU geophysicist and co-author Aleksey Smirnov discovered that the North American tectonic plate once moved an incredible 10 inches per year.

According to Smirnov, the team made the discovery on accident. They were actually studying something entirely unrelated. Every few hundred thousand years, Earth’s magnetic poles flip 180 degrees. Years ago, researchers uncovered an anomaly in the fossil magnetism records on the Keweenaw Peninsula suggesting that around one billion years ago Earth’s magnetic poles decided to go walkabout and flipped 200 degrees.

Of course, this made no sense. How could such an extreme deviation occur? What force could so strongly alter Earth’s magnetic field? The team compared their results with those of another more complete record located in Ontario. There they discovered that the tectonic plate itself had moved, not the magnetic field.

The team believes the incredible plate movement is due to significant mantle activity. The research was published in the December issue of Journal of Geophysical Research: Solid Earth under the title “Paleomagnetism of the ~1.1 Ga Coldwell Complex (Ontario, Canada): Implications for Proterozoic geomagnetic field morphology and plate velocities.”

Story Sourcing: MTU and Abstract.

Photo Credit: NASA Visible Earth

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