Deep-Sea Silverpit Crater Under North Sea Created By Asteroid Strike, Say Scientists

Buried deep beneath the seabed, about 80 miles off Yorkshire’s coast, lies an extraordinary crater that has split scientific opinion. Was it dramatically formed by an asteroid impact, or more simply caused by shifting geological salt deposits?

Today, scientists believe they have finally resolved the decades-old debate: the Silverpit crater, lying 700 metres beneath the North Sea seabed, was most likely formed over 43 million years ago by an asteroid or comet roughly the size of York Minster striking the Earth.

The 160-metre-wide asteroid smashed into the sea, causing a 100-metre-high tsunami, say scientists. It was probably a very bad day for any early mammals in the area, but not as bad as the consequences of the asteroid smash that wiped out

the dinosaurs 66 million years ago.

Experts note that while the Silverpit crater is far smaller than Mexico’s Chicxulub crater, formed when a 6- to 9-mile-wide asteroid struck Earth and wiped out about 75% of plant and animal life, it remains fascinating and highly significant as the only known impact crater near the present-day UK.

A sedimentologist from Heriot-Watt University in Edinburgh, Uisdean Nicholson, who led the research team, said new seismic imaging had given them an unprecedented look at the crater.

Getting the proof was “definitely an exciting moment”, he said, describing the investigation as “a needle in the haystack approach”.

Petroleum geoscientists discovered the crater in 2002, a two-mile-wide depression encircled by a 12-mile-wide ring of circular faults.

Those who found it believed it was indeed a hypervelocity impact crater, pointing to characteristics often associated with them, including a central peak, circular shape and concentric faults.

Initially, it was estimated to be more than 60 million years old, and it made headlines. “Crater could be asteroid strike,” read a Guardian report from the time.

However, some scientists were not convinced, arguing that it had a far less interesting origin story and it was most likely caused by the movement of salt rocks at depth.

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

In 2009, there was a debate at the Geological Society that Nicholson remembers. “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 ended 80-20 against the impact hypothesis, prompting questions about whether geologists tend to be naturally conservative. “There are different types of geologists,” Nicholson remarked. “Some say I get overly excited about certain ideas.”

Nicholson was asked to look at Silverpit because of his experience discovering another impact crater in West Africa.

Funded by the Natural Environment Research Council, Nicholson’s team employed seismic imaging, microscopic examination of rock cuttings, and numerical modelling to present what they claim is the strongest evidence to date that Silverpit is an impact crater on Earth.

Asteroid impacts are thankfully rare, with none recorded in human history. The craters they leave behind are also uncommon, as “plate tectonics and erosion erase nearly all evidence of most of these events,” Nicholson explained. “There are about 200 confirmed impact craters on land and only 33 identified beneath the ocean.”

Silverpit is exceptionally preserved and important, he said. “We can use these findings to understand how asteroid impacts shaped our planet throughout history, as well as predict what could happen should we have an asteroid collision in future.”