20020801

Stewart, S.A. and Allen, P.J. (2002) A 20-km-diameter multi-ringed structure in the North Sea. Nature 418 pp. 520-532

Researchers discoverd an possible 20 kilometer wide multiringed impactcrater deep beneath the floor of the North Sea. The reseachers estimated the age of the crater to be 60 to 65 million years old, and named it Silverpit Crater.

The structure has at least ten distinctive concentric rings located between 2 and 10 km from the crater centre, and is well preserved below several hundred metres of post-impact Tertiary strata.

From the end of the Cretaceous several impact craters are known. The best known is the Chixulub crater in Mexico with an estimated diameter 180 to 300 km, other smaller K/T impactcraters are the Gusev and Kamensk craters in the Ukraine with a diameter of 3,5 kilometer and 25 kilometer respectively. The Beyenchime crater of Russia with a diameter of 7.5 kilometer, the Eagle Butte crater in Canada with a diameter of 19 kilometer and the Upheaval Dome in the USA with a diameter of 5 kilometer. All these craters are estimated to be 65 million years old.