Two Asteroids Ended The Age of Dinosaurs Not One

We know without a shadow of doubt that around 66 million years ago, the dinosaurs were killed by an enormous asteroid that hit what is today Chicxulub, Mexico. Now, new research has revealed compelling evidence of a second major asteroid impact that occurred around the same time as the Chicxulub event. This second impact, known as the Nadir crater, is located off the coast of Guinea in West Africa.

This groundbreaking study published in Nature Communications Earth & Environment has provided unprecedented insights into the Nadir crater’s structure and formation35. Led by Dr. Uisdean Nicholson from Heriot-Watt University, the research team utilized advanced 3D seismic imaging techniques to examine the crater in exceptional detail.

“There are around 20 confirmed marine craters worldwide, and none of them has been captured in anything close to this level of detail. It’s exquisite,” Nicholson told Phys.org. “Craters on the surface are usually heavily eroded and we can only see what is exposed, whereas craters on other planetary bodies usually only show the surface expression. These data allow us to image this fully in three dimensions and peel back the layers of sedimentary rock to look at the crater at all levels.”

What were the Key Findings?

Asteroid Characteristics:
Size: Estimated to be between 450 and 500 meters wide25
Speed: Approximately 72,000 km/h (20 km/s)24
Angle of Impact: 20 to 40 degrees from the northeast5

Crater Details:
Diameter: Approximately 8.5 miles (13.7 km) wide4
Depth: Located about 300 meters below the ocean floor

Impact Effects:
Created a bowl-shaped crater
Liquefied surrounding rocks
Generated an enormous tsunami, estimated to be over 800 meters high

Significance of the Discovery

This new evidence suggests that Earth may have been struck by multiple large asteroids during the same period, potentially contributing to the mass extinction event at the end of the Cretaceous period. The Nadir crater’s age aligns closely with that of the larger Chicxulub crater in Mexico, which measures 125 miles (200 km) in diameter.

Dr. Nicholson likened the advancement in imaging technology to the evolution of medical ultrasounds, stating, “We’ve gone from 2D, fuzzy imaging to amazing high-resolution imaging of the Nadir Crater.”

The research team plans to drill into the seabed to collect core samples from the crater, which could provide more precise information about the impact’s age, shock pressures experienced during the event, and the sequence of events that followed.This discovery not only enhances our understanding of Earth’s geological history but also offers valuable insights into impact processes and crater formation, which can be applied to understanding similar events on Earth and other celestial bodies.

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Saima Baig

I am a Chartered Environmentalist from the Royal Society for the Environment, UK and co-owner of DoLocal Digital Marketing Agency Ltd, with a Master of Environmental Management from Yale University, an MBA in Finance, and a Bachelor of Science in Physics and Mathematics. I am passionate about science, history and environment and love to create content on these topics.