Scientists have found evidence of another asteroid impact, however, this one is not on the surface. The asteroid crashed into the Atlantic Ocean, leaving behind a massive 8.5-kilometer-wide crater in the seabed. The crater has been found nearly 400 meters below the seabed, nearly 400 kilometers off the coast of Guinea, west Africa.
While the finding is yet to be confirmed, scientists are hopeful that if they are able to drill into the seabed and collect samples, they could prove the theory of the asteroid impact that likely happened 66 million years ago – around the same time that the Chicxulub asteroid hit Earth and wiped out the dinosaurs.
Their findings have been published in the journal Science Advance, which states that the crater formed as part of a closely timed impact cluster or by the breakup of a common parent asteroid. “Hypervelocity impacts of large asteroids or comets with Earth are still poorly understood despite the risk they pose,” researchers said in the paper.
Researchers using computer simulation managed to scope out the crater and identify the causes and effects of the massive crash. The simulation indicated that the crater was formed by the collision of a 400-meter-wide asteroid in 500-800 meters of water, that could have generated a tsunami over one kilometer high, as well as an earthquake of magnitude 6.5 or above.
A: the impactor hits the water surface at a velocity of over 20 km/s, initiating a rim-wave tsunami in its wake. (B) Several seconds later, the transient crater forms. (Photo: Science Advance)
“The energy released would have been around 1000 times greater than that from the January 2022 eruption and tsunami in Tonga. These are preliminary simulations and need to be refined when we get more data, but they provide important new insights into the possible ocean depths in this area at the time of impact,” Dr. Veronica Bray, a planetary scientist at the University of Arizona said in a statement.
A DANGEROUS IMPACT
The crater was discovered by Dr. Uisdean Nicholson, a geologist at Heriot-Watt University in Edinburgh when he was examining the seismic reflection from the seabed of the Atlantic. Instead of flat sedimentary sequences in the seismic reflection, he found an 8.5km depression under the seabed, with very unusual characteristics.
“It has particular features that point to an asteroid. It has a raised rim and a very prominent central uplift, which is consistent for large impact craters. It also has what looks like ejecta outside the crater, with very chaotic sedimentary deposits extending for tens of kilometers outside of the crater,” Dr. Uisdean Nicholson said in a statement.
The crater was formed by the collision of a 400-meter-wide asteroid. (Photo: Getty)
Naming it Nadir crater after a nearby seamount, the researcher maintains that the characteristics are just not consistent with other crater-forming processes like salt withdrawal or the collapse of a volcano.
WAS IT PART OF THE SAME ASTEROID THAT WIPED OUT DINOSAURS?
Analysis of seismic data revealed that sediments impacted by the asteroid correspond with the Cretaceous-Paleogene boundary, however, they are not yet sure due to the resolution of the seismic data. The period corresponds to the age when the asteroid that wiped out dinosaurs from Earth came crashing down.
While the team speculates that it could be part of the impact cluster or a breakup of a common parent asteroid, Dr. Sean Gulick, an impact expert at the University of Texas at Austin, said, “The Nadir Crater is an incredibly exciting discovery of a second impact close in time to the CretaceousPaleogene extinction.
So far only 200 such impact sites have been found in the 4.5-billion-year history of the planet.
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