The only thing worse than being punched in the face is being punched twice. Scientists now say that’s almost exactly what happened to dinosaurs – just on a much larger scale. The asteroid that hit Chicxulub in Mexico is still believed to have wiped out the dinosaurs, but around the same time a second asteroid hit the Nadir crater off the coast of Guinea in west Africa, making it clear that nature really caused it. I proved it once and for all. Poor dinosaurs.
new research Published in Nature magazine It shows off the nadir crater in a way that science has never been able to observe before. Scientists led by geologist Wisdean Nicholson from Scotland’s Heriot-Watt University used 3D seismic data to measure the impact and reverse engineer the asteroid’s size, impact angle, impact velocity, and impact severity. I was able to. It was on the ocean floor or on the rocks beneath it.
According to the study, the asteroid was probably 450 to 500 meters in size, traveling at 20 kilometers per second, and struck Earth at an angle of 20 to 40 degrees from the northeast.
“There are about 20 marine craters that have been identified around the world, but none have been photographed in such detail. It’s very beautiful.” Nicholson told Phys.org.. “Craters on the Earth’s surface are typically heavily eroded and only visible as they are exposed, whereas craters on other planets typically only show surface expressions. These data allow us to completely clarify this. “We can image it in three dimensions and peel back the layers of sedimentary rock to see the crater at all levels.” ”
Among other things, the study proved that this crater was actually the result of an asteroid impact, which occurred around the same time as the asteroid that wiped out the dinosaurs, 66 million years ago at the end of the Cretaceous period. period. So while it was the Chicxulub asteroid that wiped out the dinosaurs, the asteroid that hit Nadir Crater may have given them some help.
Structure of asteroid impact
The asteroid would have hit with incredible violence, displacing water in the area for up to a minute.
Perhaps even more frightening were the sequential consequences of the shock, which scientists were also able to reproduce. According to the study, the asteroid displaces all the water in the area, which was about 800 meters deep at the time, and sends a huge “tsunami train” into the Atlantic Ocean.
The spit may have formed as sediment poured in to fill the new hole created by the impact. Some of the sediment may have evaporated during the impact. The tsunami was measured to have affected the ocean floor more than 20 kilometers away.
When a major earthquake occurred from there, it is thought to have caused damage beneath the ocean floor, including liquefaction of the foundation rock in the entire area near the crater. The tsunami train eventually reverses and water returns to fill the area again.
In addition to all this, scientists say the shock would have caused ionospheric disturbances and thermal radiation. If part of the undersea plateau crashed further into the ocean, a massive landslide would have occurred.
Fortunately for humans, this type of shock is extremely rare. The largest meteorite impact in living memory was the “Superbolide” asteroid that exploded over Russia in 2013. Although it is highly unlikely that a similarly sized asteroid, Bennu, will collide with Earth around 2300, the probability is as follows: Approximately 1 in 1,750 people.
