43M-Year-Old Impact Formed Rare Undersea Crater

Scientists have finally confirmed that a mysterious crater half a mile beneath the North Sea was carved out by a massive asteroid strike more than 43 million years ago—ending decades of debate over its origin. The Silverpit crater, discovered 80 miles off the Yorkshire coast by petroleum geoscientists in 2002, has been at the center of controversy, with some believing it to be the result of an asteroid or comet impact, while others pointed to more routine geological processes like salt rock movement or seabed collapse triggered by volcanic activity, per the Guardian and BBC. New research led by sedimentologist Uisdean Nicholson of Edinburgh's Heriot-Watt University offers what he describes as the clearest evidence yet for an impact origin.

Using advanced seismic imaging, microscopic analysis of rock samples, and computer modeling, Nicholson's team concluded that the roughly 2-mile-wide crater was likely formed by a 525-foot-wide asteroid crashing into the sea at a low angle from the west more than 43 million years ago, according to the study published Saturday in Nature Communications. Nicholson says rare "shocked" quartz samples from a nearby oil well, located at the same depth as the crater floor, proved the impact crater theory as they could "only be created by extreme shock pressures," per the BBC and a release. Though not on the scale of the impact that wiped out the dinosaurs, the event would have triggered a tsunami reaching 328 feet in height.

Despite its relatively modest size compared to the Chicxulub crater in Mexico, Silverpit is notable as the only confirmed impact crater near what is now the UK, per the Guardian. There are only about 200 confirmed impact craters on land and 33 beneath the oceans worldwide. The site, concealed under the seabed and surrounded by concentric faults, is also well-preserved, a rarity since erosion and plate tectonics typically erase such evidence over time. Nicholson says the new findings can help researchers better understand how asteroid impacts have shaped Earth's history, as well as inform future risk assessments.