On impact, the conventional explosives in the nuclear weapons detonated, but fortunately did not trigger a nuclear explosion. Nevertheless, radioactive material was scattered over a wide area.

The Northern Isles, which consist of the two island groups of Shetland and Orkney, have been inhabited since prehistoric times but were formally annexed by the Norwegian king Harald Hårfagre in around 875 after he subdued the Vikings who used the islands as a base from which to raid Norway and Scotland.