The World’s First Conclusively Proven Double Crater Found in Sweden
Looking into traces of two massive meteorite impacts found in the Swedish county of Jämtland, researchers at the University of Gothenburg have discovered a uniquely rare twin-meteorite strike that occurred at the same time, some 460 million years ago.
Erik Sturkell, a Professor of Geophysics at the University of Gothenburg, made the revelation, in an article published on the University’s website.
“The two meteorite impacts occurred at the same time, 458 million years ago, and formed these two craters.”
Sturkell and his team of researchers disclosed the details of their discovery in the Swedish county of Jämtland by noting that:
- The first crater, enormous in its size with a diameter of 7.5 kilometers (4.1 miles) was discovered 20 kilometers (12.7 miles) south of Östersund in Brunsflo.
- The second crater, smaller in comparison at 700 meters (.43 miles) in diameter was found 16 kilometers (9.16 miles) from the first crater.
A Time When Meteorites Rained on the Earth
The discovery of the two meteorites impacting the Earth 458 million years ago aren’t the only ones to rain down on the earth’s surface at the time, Strukell contends.
“Around 470 million years ago, two large asteroids collided in the asteroid belt between Mars and Jupiter, and many fragments were thrown off in new orbits. Many of these crashed on Earth, such as these two in Jämtland,” he says.
At the time, Jämtland was under the sea, with a water depth of half a kilometer at the points of impact where the meteorites struck at the same time. These simultaneous double-impacts are exceedingly rare, making this case the first double impact on earth that has been discovered to be conclusively proved.
Researchers used data and parallel signs from drilling operations to deduce that the impacts occurred at the same time.
“Information from drilling operations demonstrates that identical sequences are present in the two craters, and the sediment above the impact sequences is of the same age.”
“In other words, these are simultaneous impacts,” Sturkell explains.
In a reimagining reminiscent of a disaster movie, the water was pushed away from the sheer force of the impact, leaving the seabed completely dry for a hundred seconds.
The water then rushed back in, bringing with it fragments from the meteorites mixed with material that had been ejected during the explosion and with the gigantic wave that tore away parts of the seabed.
Researchers admit that active quarrying in the region is the reason as to why meteorites are regularly discovered in the area. In the 1940s, slabs of limestone have shown fragments of a meteorite, researchers note. It isn’t entirely out of the realm of possibility that the next piece of limestone you find yourself standing on might contain readily visible meteorite fragments and minerals.
“Technically speaking, yes, although there is probably not much chance, as the limestone slabs that come from meteors are often rather ugly and will probably have been discarded. But they do exist!,” confirmed Sturkell.
Images from Shutterstock and Pixabay.