UK impact crater debate heats up By Jonathan Fildes Science and technology reporter, BBC News Seismic surveys show a trough surrounded by concentric fractures A deep scar under the North Sea thought to be the UK's only impact crater is no such thing, claims a leading geologist. Professor John Underhill, from the University of Edinburgh, says the Silverpit structure, as it is known, has a far more mundane explanation. Detailed surveys reveal nine similar vast chasms in the area, he says. This suggests it was part of a more widespread process, probably the movement of salt rocks at depth, not...