Beaufort's Dyke


Beaufort's Dyke is a natural trench between Northern Ireland and Scotland within the North Channel. The dyke is long, wide and deep.

Geomorphology

Beaufort's Dyke is a submerged tunnel valley caused by glacial erosion during the last glacial period, and has been prevented from filling with sediment by strong tidal currents.

Dumped munitions

Because of its depth and its proximity to the Cairnryan military port, Beaufort's Dyke became the United Kingdom's largest offshore dump site for surplus conventional and chemical munitions after the Second World War: it had been used for the purpose since the early 20th century. The Ministry of Defence estimated that well over a million tonnes had been disposed there. In July 1945, 14,500 tonnes of artillery rockets filled with phosgene were dumped.
Munitions have since been deposited by the tide on nearby beaches. In 1995, phosphorus bombs washed up on Scottish coasts, coinciding with the laying of the Scotland-Northern Ireland pipeline, a gas interconnector constructed by British Gas. In the prior five years, antitank grenades had been washing up on Northern Irish and Isle of Man shores.
Explosion registered as a 2.5 Magnitude earthquake 08 Feb 1986 https://earthquake.usgs.gov/earthquakes/eventpage/usp0002qu8/executive

Nuclear waste

According to documents from the Public Record Office, approximately two tonnes of concrete-encased metal drums filled with radioactive laboratory rubbish and luminous paint were dumped in the dyke during the 1950s.

Crossings

Projects for a tunnel or Irish Sea fixed crossing between Northern Ireland and Scotland have been suggested at various times from the late 19th century onwards. The dyke has always been an important problem for such proposals, in terms of both practicality and cost.
In February 2020, the UK government announced an initial investigation into a Scotland–Northern Ireland bridge. Two possible routes were proposed: Portpatrick–Larne and Kintyre peninsula–Torr Head. The Portpatrick route would cross the dyke. Explosive ordnance advisers Exord cast doubt on the Portpatrick route saying “any intrusive works such as piling associated with the construction of bridges would pose an unacceptable level of risk”.