where was it found this time? In the Atlantic Ocean, off the coast of West Africa. It would be the crater of the second large asteroid to hit our planet. One less than the asteroid that killed the dinosaurs. It happened 66 million years ago.
It was christened Nadir crater. The new feature is hidden under about 900 meters of water and 400 meters of sediments. It has not yet been studied directly. It was detected in seismic wave reconstructions of the ocean floor.
Fireball
Nadir’s shape is diagnostic of an asteroid impact. It has a raised rim surrounding a central uplift zone. Beyond that, layers of debris extend outward.
Researchers calculated that the asteroid hit the ocean floor with a power of 5,000 megatons of TNT. It would have produced a fireball 10 km wide. It was capable of generating a magnitude 7 earthquake. It caused submarine landslides, responsible for the formation of some major waves.
“This would have generated a tsunami more than a kilometer high. The energy released would have been gigantic. A thousand times greater than the January 2022 eruption and tsunami in Tonga.” Details Dr. Veronica Bray of the University of Arizona.
Another possibility
The crater was identified by Dr. Uisdean Nicholson of Heriot-Watt University, Edinburgh. He was analyzing data from seismic surveys. He wanted to understand past climate changes on Earth.
The impact site is not as large as the Chicxulub crater in Mexico. This one was left by the asteroid that wiped out the dinosaurs. However, it is very similar in age. Seismic data allow Nicholson and his team to estimate the age of the new crater. There is another option: that Chicxulub broke into two parts.
The crater of the second large asteroid can be studied even further. They would have to drill into the ground and extract rock samples. There may still be small fragments of asteroids embedded in the crater, scientists say.
