admin Studies show that between 79 and 86 million years ago, the Earth tilted to its side and recovered. About 84 million years ago, at the end of the Cretaceous period, when Tyrannosaurus and Triceratops ruled the Earth, the Earth tilted 12 degrees before recovering.
“The Earth’s 12-degree tilt could have a similar effect on latitude,” Sarah Slotnick, a geobiologist at Dartmouth College and co-author of the new study, told Business Insider. With this tilt of the Earth, New York City, USA, would be roughly in the same position as Tampa, Florida is today.
The researchers found that between 86 and 79 million years ago, the crust and mantle rotated around the Earth’s outer core and ridges, causing the entire planet to tilt and then flip like a fin. It has been found. play.
By analyzing paleomagnetic data, scientists can create images that show where tectonic plates were millions of years ago. As lava cools at the junction of two plates, some of the rock layers contain magnetic minerals that correspond to the orientation of the Earth’s magnetic poles when the rock solidified.
Even after rock-bearing plates have moved, researchers can study this magnetic alignment to analyze where natural magnets once existed on the world map. .
The researchers studied the magnetic orientation of ancient limestone from Italy and found that it moves about three degrees every million years as the earth’s crust tilts and rotates.
Think of the Earth as a gyroscope. If the weight of the top is evenly distributed, the top will rotate perfectly without wobbling. However, moving some of the mass to either side changes the center of gravity of the comb, causing it to lean to the heavier side as it rotates. The accumulation of hot rock and magma from the outer core to the crust, known as the mantle plume, may have played a role in the change in Earth’s mass distribution during the Cretaceous, according to researcher Slotznick. Late white.
Co-author Ross Mitchell, a geophysicist at the Chinese Academy of Sciences, noted that shifting tectonic plates could explain the ancient Earth’s 12-degree tilt. As hotter, less dense material from deep in the mantle rises toward the crust and cooler, denser material sinks toward the core, tectonic plates can collide. In a collision, one board collapses under the other.
Before the Late Cretaceous, the Pacific Plate—the largest tectonic plate on Earth, covering millions of square miles beneath the Pacific Ocean—was submerged to the north by another plate. About 84 million years ago, the Pacific Plate began to slide in a different direction, under another plate to the west.According to Mitchell, this shift may have altered the Earth’s balance. So he wasn’t surprised when the earth changed direction and tilted backwards.
“The outer layer of the planet behaves elastically like a rubber band and will return to its original shape after deviating from the axis,” he said.
