An astonishing new finding by scientists from Heriot-Watt University may rewrite the history of Earth's ancient mass extinctions.
Researchers have uncovered a second asteroid impact site named Nadir Crater, suggesting two massive asteroids may have struck our planet simultaneously around 66 million years ago, The Independent reported.
The long-held belief maintained by scientists was that a singular catastrophic event, caused by a six-mile-long asteroid, led to the extinction of dinosaurs.
This impact formed the 124-mile-wide Chicxulub Crater under what is now the Gulf of Mexico’s Yucatán Peninsula. However, the recent discovery off the coast of West Africa introduces a new concurrent chapter to this extinction storyline.
Dr. Uisdean Nicholson and his team unearthed Nadir Crater, located beneath nearly one thousand feet of sediment in the Atlantic Ocean. It took over five years from initial discovery to its confirmation, relying heavily on refined seismic data that revealed the crater in unprecedented three-dimensional detail.
Nadir Crater is significantly smaller than Chicxulub but still formidable, measuring five miles in width with a rim spanning 9,200 meters. Surrounding the rim is a 22,000-meter-wide brim, which Dr. Nicholson describes as a set of concentric circular features resulting from the seabed collapsing inward post-impact.
The detailed imagery used to identify and analyze Nadir Crater was provided by TGS, a global geophysical company. This technology provided a clear three-dimensional view of the crater, akin to a medical CT scan.
Dr. Nicholson likened the clarity and detail of this data to a leap from old X-ray images to comprehensive CT scans, offering unprecedented insight into the Earth's geological past.
Further analyses suggest that the asteroid responsible for Nadir Crater was over 1,300 feet wide, dwarfing any observed in human history in terms of size.
Upon entering Earth’s atmosphere, the asteroid would have transformed into a massive fireball, creating an explosion thousands of times more powerful than the 2022 Tonga volcanic eruption.
The impact is estimated to have generated a magnitude 7.0 earthquake and provoked tsunamis, adding to the environmental catastrophes of the time. These findings were recently published in the esteemed journal "Nature Communications Earth & Environment."
In their upcoming research phase, Dr. Nicholson's team plans to drill into the ocean floor where Nadir Crater sits. Their objective is to retrieve samples that could offer more detailed insights into the impact and its effects on our planet's geology and biology.
Such data could prove crucial in understanding not only the crater’s direct consequences but also its role in broader geological and environmental processes.
Dr. Nicholson detailed his findings, emphasizing the significance of these geological structures. He explained the layout of Nadir Crater's key features, from the main rim to the extended brim, which marks where the ocean bed was abruptly forced downwards due to the asteroid's immense impact.
"It reveals this crater in three dimensions for the first time – the first time we’ve ever been able to see inside an impact crater," Dr. Nicholson expressed to The Independent, highlighting the groundbreaking nature of this research.
This discovery challenges the previously accepted scenario that a single asteroid caused the end of the dinosaurs. Instead, it suggests that Earth faced nearly simultaneous impacts, contributing to the Cretaceous-Paleogene extinction event, one of the most significant losses of life in Earth’s history.
The size and impact of the asteroid that created Nadir Crater could reshape our understanding of planetary disruptions and their effects on evolutionary history.
Such revelations underscore the dynamic and sometimes violent nature of Earth’s geological history and provide insights that may prove pivotal for current and future geological research.
With plans to explore further and gather more evidence from the ocean depths, Nicholson and his team stand at the forefront of potentially transformative paleogeological discoveries. "We haven't had anything like this in human history," remarks Nicholson, underscoring the exceptional nature of the Nadir impact in Earth's geologic record.
