They find a crater that is believed to have been a second asteroid that caused the extinction of the dinosaurs

The Nadir crater is located in the Atlantic Ocean, off the coast of Guinea. It is believed that it was made by another asteroid that ended up wiping out the dinosaurs .

Evidence of an asteroid impact crater 8.5 kilometers in diameter has been identified 300-400 meters deep in the Atlantic, 400 kilometers off the coast of Guinea in Africa.

A team of researchers from Heriot-Watt University believe the crater was caused by a 400-meter-wide asteroid that collided with Earth about 66 million years ago, around the same time the Chicxulub asteroid hit Earth and ended with the dinosaurs .

But they will need to drill into the seabed and collect samples to prove their theory. If confirmed, the crater will be one of fewer than 20 confirmed marine impact craters found on Earth. The discovery is reported in Science Advances .

This is how the crater was found

Dr. Uisdean Nicholson, a geologist at Heriot-Watt University in Edinburgh, found the crater by examining seismic reflection from the Atlantic seafloor.

“I’ve interpreted a lot of seismic data in my time, but I’ve never seen anything like this. Instead of the flat sedimentary sequences I was expecting on the plateau, I found an 8.5km depression under the seafloor, with very unusual features,” he said in a statement.

“It has particular features that point to an asteroid . It has a raised rim and a very prominent central bulge, which is consistent for large impact craters.

“It also has what looks like material ejected out of the crater, with very chaotic sedimentary deposits extending for tens of kilometers outside the crater .

“The features are simply not consistent with other cratering processes such as salt mining or volcano collapse.”

Nicholson has named it Nadir Crater , after a nearby seamount.

Seismic data also indicate that the sediments impacted by the asteroid correspond to the Cretaceous-Paleogene boundary. However, there is some uncertainty due to the resolution of the seismic data.

This is the same age as the Chicxulub crater that killed the dinosaurs . The team believes that the asteroid that created the newly discovered Nadir crater could have been formed by the breakup of a parent asteroid or by an asteroid flow in that time period.

Dr Sean Gulick, impact expert at the University of Texas at Austin, said: ” Nadir Crater is an incredibly exciting discovery of a second impact near the Cretaceous-Paleogene extinction event.

“While it is much smaller than the extinction caused by the Chicxulub impactor, its very existence compels us to investigate the possibility of a Late Cretaceous impact cluster.”

“Despite four billion years of impactors hitting Earth, only 200 have been discovered. So it’s exciting news every time a new potential impact is discovered, especially in the hard-to-explore marine environment.”

The theory behind Nadir

The scientists used computer simulations to determine what kind of collision took place and what the effects might have been.

Dr Veronica Bray, a planetary scientist at the University of Arizona, said: “Our simulations suggest that this crater was caused by a 400m wide asteroid colliding in 500-800m of water. This would have generated a tsunami of more one kilometer high, as well as an earthquake of magnitude 6.5 more or less.

“The energy released would have been around 1,000 times that of the January 2022 Tonga eruption and tsunami. These are preliminary simulations and need to be refined when we get more data, but they do provide important new insights into the potential ocean depths in this area at the time of impact.

Nicholson has already applied for funding to drill into the seafloor to confirm that it is an asteroid impact crater and prove its precise age. ( EuropaPress )