GabyDeep beneath the Atlantic Ocean, the Nadir crater was formed around the same time as the Chicxulub crater, which was left behind by the asteroid that wiped out the dinosaurs at the edge of the Yucatán Peninsula. Scientists have long known that about 66 million years ago, a massive asteroid over 10 kilometers in diameter collided with Earth, leading to the extinction of 75 percent of animal and plant species. This impact created a crater measuring 180 kilometers across, known as Chicxulub. Now, researchers assert that a smaller space rock also struck our planet around the same time, creating the Nadir crater, which lies more than 9 kilometers wide deep beneath the Atlantic. Two years ago, it was discovered at a depth of 300 meters off the coast of West Africa by researcher Visdin Nicholson from Heriot-Watt University in Edinburgh. According to Dr. Nicholson, this crater formed at the end of the Cretaceous period. However, the exact circumstances of that event have remained unclear until now. Thanks to a new study, during which scientists finally mapped Nadir in extraordinary detail, much more has been revealed about its formation.
What did the researchers find out? Using high-resolution 3D seismic data, Dr. Nicholson’s team was able to determine “beyond a reasonable doubt” that the crater was formed by the impact of a space rock. “This is the first time an impact structure has been fully depicted using high-resolution seismic data, and this true source of information will help us reconstruct how this crater was formed and evolved,” stated the lead researcher. He noted that “there are about 20 confirmed marine craters in the world, but none have been depicted at such a level of detail.” This allowed the team to gain a clearer picture of what happened at that time. For instance, scientists now know that the previously unknown asteroid was larger than previously thought, measuring between 450 and 500 meters wide. The team reported that it struck Earth at a speed of 72,000 kilometers per hour. Additionally, the research shed light on the timeline of events that occurred as a result of the impact. “After the impact and the formation of the central uplift, the soft sediments surrounding the crater flowed inward to the evacuated floor, creating a visible ‘edge.’ The earthquake caused by the impact likely liquefied the sediments beneath the seabed across the plateau, leading to the formation of faults on the ocean floor,” explained Dr. Nicholson. He added that the asteroid’s impact triggered a tsunami that reached heights of 800 meters. “The impact was also associated with significant landslides, as the edge of the plateau collapsed into the ocean. Furthermore, we see evidence that a series of tsunami waves bypassed the crater and then returned to it with large scars from the re-ejection, preserving evidence of this catastrophic event,” the scientist elaborated.
Why is this knowledge important? Researchers are currently trying to date this event as accurately as possible. They also aim to determine any potential connection between this crater and Chicxulub, as reported by IFLScience. According to Dr. Visdin Nicholson, there have been no collisions with such gigantic asteroids in the history of our planet. Therefore, studying this topic could prove extremely valuable. Not only will it help us learn more about the end of the dinosaurs’ reign, but it will also enhance our understanding of the nature of asteroid impacts on Earth. “The closest we’ve come to understanding something like this was after the Tunguska event in 1908,” Dr. Nicholson said. He believes that “obtaining new 3D seismic data about Nadir is an unprecedented opportunity to test hypotheses about impact craters, develop new models of their formation in marine environments, and understand the consequences of such events.” The results of the study were published in the journal Communications Earth & Environment.
