A marine crater located 80 miles off the coast of Yorkshire has been the subject of scientific debate for years. Was the Silverpit crater formed by an asteroid strike, or by the movement of geological salt? New research has resolved the question.

The Silverpit crater, situated 700 meters below the seabed in the North Sea, was most likely created by an asteroid or comet approximately the size of York Minster. According to researchers, the object struck the earth over 43 million years ago.

Scientists estimate the 160-meter-wide asteroid caused a 100-meter-high tsunami when it crashed into the sea. While this event would have been devastating for any mammals in the area, its impact was far less severe than the asteroid strike that led to the extinction of the dinosaurs 66 million years ago.

The Silverpit crater is significantly smaller than the Chicxulub crater in Mexico,which was created by an asteroid roughly 6 to 9 miles wide. The Chicxulub impact resulted in the extinction of 75% of plant and animal species. Experts say that despite its smaller size, the Silverpit crater is notable as the only impact crater near the UK.

Uisdean Nicholson, a sedimentologist from Heriot-Watt University in edinburgh and leader of the research team, stated that new seismic imaging provided an unprecedented view of the crater.

Nicholson described the inquiry as “a needle in the haystack approach,” adding that obtaining the proof was “definitely an exciting moment”.

The 2-mile-wide crater, surrounded by a 12-mile wide zone of circular faults, was discovered in 2002 by petroleum geoscientists.

The discoverers posited that it was a hypervelocity impact crater, citing features commonly associated with such formations, including a central peak, circular shape, and concentric faults.

Initial estimates placed its age at over 60 million years, leading to headlines such as “Crater could be asteroid strike”.

However, some scientists remained skeptical, suggesting a less dramatic origin involving the movement of salt rocks at depth.

“I feel like I’m spoiling the party,” said the geologist Prof John Underhill, from the University of Edinburgh, who led the doubters at the time. “It’s a less glamorous description, but that’s what the scientific data is saying.”

Nicholson recalls a debate at the Geological Society in 2009.”I was a PhD student at the time and it was quite a well-known debate, within geological circles at least.

“They had the big debate and then they had a vote. It was overwhelmingly decided that it was a non-impact origin. most people favoured the mundane explanation and I think that reflects a tendency to reject the more spectacular explanation.”

The vote was 80-20 against the impact hypothesis, which raised the question of whether geologists are naturally conservative. “There are different flavours of geologist,” said Nicholson. “People say I get too excited by certain ideas.”

Nicholson’s experience discovering another impact crater in west Africa led to his involvement with the Silverpit investigation.

Funded by the Natural Environment Research Council, Nicholson’s team employed seismic imaging, microscopic analysis of rock cuttings, and numerical models to provide what they believe is the strongest evidence to date that Silverpit is indeed an impact crater.

“definitely an exciting moment”

Asteroid impacts are rare events, with none occurring in recorded human history. Impact craters are also scarce due to plate tectonics and erosion, which erase most traces of these events. According to Nicholson, “Around 200 confirmed impact craters exist on land and only 33 have been identified beneath the ocean.”

Nicholson emphasizes the exceptional preservation and importance of Silverpit. “We can use these findings to understand how asteroid impacts shaped our planet throughout history, and also predict what could happen should we have an asteroid collision in future.”

The findings are published in Nature Communications.