British and American scientists have found by analyzing seismic data off the coast of West Africa compelling evidence of the existence of a possible large underwater crater from an asteroid impact.

Researchers led by Associate Professor of Geological and Geosciences Wisdin Nicholson of the Scottish University of Heriot-Watt, who made the corresponding publication in the journal Science Advances, calculated that the crater has an age of 66 million years, similar to the famous and much larger Chicxulub. a crater 200 km in diameter in the Gulf of Mexico, which was associated with the fall of a large asteroid with a diameter of 10-12 km, which led to the mass extinction of flightless dinosaurs (as well as three-quarters of all plant and animal species) at the end of the geological Cretaceous period.

Nadir, the African crater at least 8.5 kilometers in diameter was named, is buried under sediments 300 to 400 meters thick on the seabed, at a sea depth of 900 meters, about 400 km off the coast of Guinea in West Africa. Scientists do not exclude that the two craters – Chicxulub and Nadir – are interconnected.

If it is confirmed that Nadir was created by an asteroid impact, the researchers believe it is possible that there was originally a larger parent asteroid that, when falling to Earth, broke up into smaller pieces in the atmosphere, large enough to cause cataclysms. Alternatively, there could originally have been two separate asteroids – or more, whose craters have not yet been discovered – that fell in close proximity to each other.

Seismic analysis and subsequent modeling led to an estimate that the asteroid had a diameter of about 400 meters and should have fallen with a force equivalent to an explosion of 5,000 megatons of TNT into a sea 800 meters deep, successively causing a huge earthquake. a tsunami up to a kilometer high, an earthquake of 6.5 to 7 degrees, and possibly the release of a significant amount of greenhouse gases from carbon deposits on the seabed.

^{Source: RES-IPE}