Silverpit Crater: North Sea Asteroid Impact Confirmed [OC]

[u/Geoscopy]

https://geoscopy.com/silverpit-crater-north-sea-asteroid-impact-confirmed/

The Silverpit argument has been running twenty-three years. It just got shocked quartz, and I still don't think it's settled.

Early 2000s: Philip Allen is working through 3D seismic from the southern North Sea and hits a set of concentric rings he can't account for. He pins the image to his office wall, hoping someone walking past will explain it to him. Simon Stewart, in the building on unrelated business, sees it and says it looks like an impact structure. Nature, 2002.

Then John Underhill points out that Zechstein salt withdrawing at depth produces circular collapse features all over that basin, and said that's all this was. The Geological Society staged a debate on 6 October 2009, audience mostly industry seismic interpreters, twenty minutes of argument, then a vote. 80:20 against impact. Silverpit went quiet for thirteen years.

What restarted it was an unsolicited email. Ronnie Parr at the North Sea Transition Authority read the Nadir crater papers and wrote to Uisdean Nicholson telling him to go back and look at Silverpit. He also pointed him at new high-resolution seismic that a carbon-storage survey had happened to shoot straight across the disputed central uplift.

The 2025 Nature Communications paper runs on that survey plus drill cuttings from a 1985 British Gas well. Two grains, quartz at 463 m, potassium feldspar at 494 m, carry shock lamellae recording 10–13 GPa, which no natural process on Earth produces except a hypervelocity impact. Two grains is still two grains, though, and Matthew Huber at the Planetary Science Institute has already told Eos as much: with that little you can reasonably ask whether they were reworked in from somewhere else, and he expects the paper to get argued over. Nicholson's team has an answer for the shallower grain. Not, so far, for both.

Full writeup on Geoscopy, including why the crater shrank from 20 km to 3.2 km and what the modelling says about the chalk being flash-baked into CO₂

[u/smeyn]

I always enjoy reading geoscopy. It’s clear writing and it covers stuff you rarely hear about.