In the past, less has been known about the ocean floor than about the surface of Mars. Also, when our team of experts looked at the seabed and ancient sediments below, they found what looks like an asteroid impact crater.
It’s interesting to note that the Chicxulub impact, which happened at the end of the Cretaceous period about 66 million years ago and killed off the dinosaurs and many other species, is the same age as the crater called Nadir after the nearby volcano Nadir Seamount.
Science Advances wrote about the find, which makes people wonder if there is a link between the crater and Chicxulub. If it were true, it would also be very important for science in general because it would be one of the few known cases of an asteroid hitting a ship at sea. This would give scientists new, original information about what happens during such a collision.
Using seismic reflection, the crater was found as part of a larger project to figure out how the continents of South America and Africa moved apart during the Cretaceous period. Like ultrasound data, seismic reflection works by sending pressure waves into the ocean and picking up the energy that comes back. With this information, geophysicists and geologists can figure out how the rocks and sediments are put together.
After finding and studying the crater, we made computer simulations of an impact to see if we could copy the crater and describe the asteroid and its impact.
The most accurate simulation is one where an asteroid 400 metres across hits an ocean 800 metres deep, making a crater 800 metres across. When something hits the ocean at those depths, it causes a lot of damage. It would cause a column of water 800 metres thick, the asteroid and a lot of mud to evaporate right away, and a huge fireball that could be seen from hundreds of kilometres away.
The collision would cause shock waves as strong as a magnitude 6.5 or 7 earthquake, which would probably cause underwater landslides in the area. A tsunami wave train would start to form.
The air blast from the explosion would be the largest ever heard on Earth. About a thousand times more energy would be released than in the last Tonga eruption. It is also likely that the pressure waves in the air will make the tsunami waves bigger and send them even further from the crater.