Hurd Deep from cropped Admiralty Chart No 2649 English Channel Western Portion Published 1955

Admiralty Chart No 2649 English Channel Western Portion Published 1955

Hurd's Deep (or Hurd Deep) is an underwater valley in the

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

, northwest of the

Channel Islands The Channel Islands are an archipelago in the English Channel, off the French coast of Normandy. They are divided into two Crown Dependencies: the Jersey, Bailiwick of Jersey, which is the largest of the islands; and the Bailiwick of Guernsey, ...

. Its maximum depth is about 180 m (590 ft; 98 fathoms), making it the deepest point in the English Channel.

Toponym

The feature was named after the British Royal Naval Captain Thomas Hurd (1747–1823), who was the second

Hydrographer of the Navy The Hydrographer of the Navy is the principal hydrographical Royal Naval appointment. From 1795 until 2001, the post was responsible for the production of charts for the Royal Navy, and around this post grew the United Kingdom Hydrographic Office ...

. It was chosen by the RN marine cartographer Admiral Martin White.

Geology

Hurd's deep began to form in the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

of the late

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

period (in the last 750,000 - 500,000 years). Successive melting periods after

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

s caused water to gouge out a deep water trench through a river valley system that now forms the seabed in the eastern part end of the English Channel. At some point a catastrophic flood from the southern

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

basin created Hurd's Deep. It's believed that the collapse of a chalk ridge that once dammed the

Strait of Dover The Strait of Dover or Dover Strait, historically known as the Dover Narrows, is the strait at the narrowest part of the English Channel, marking the boundary between the Channel and the North Sea, and separating Great Britain from continental ...

let flood waters from a huge proglacial lake flow through the former river systems scouring down to the bedrock forming the trench. During the Last Glacial Period, which ended 11,700 years ago, sea levels dropped again to the point that the English Channel became an area of river valleys. Due to its depth, Hurd's Deep likely remained flooded by seawater. It might have been a glacial refugium. Hurd's Deep has an approximate length of with a width of between . It terminates abruptly at the western end. The seafloor around the trench is typically flat with a depth range of . But within the trench the maximum depth is . Hurd's Deep is the deepest point in the English Channel.

History

Deep sea ordnance disposal

Following the

First World War World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, Hurd's Deep was used by the British Government as a dumping ground for both chemical and conventional munitions. Following the Second World War, it was used to dump military equipment, munitions and weaponry left behind by the ousted German invaders of the Channel Islands. Routine dumping of British munitions carried on until 1974. Between 1946 and 1973 the area was also used for the dumping of low- and intermediate-level

radioactive waste Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear ...

s. 28,500 barrels of waste – including plutonium, which has a half-life of 24,100 years – were disposed of into the Deep during this period.

Wrecks

was scuttled there in 1921. The British submarine sank in Hurd's Deep in 1951 with the loss of 75 lives.

In popular culture

In Harry Collingwood's

science fiction Science fiction (often shortened to sci-fi or abbreviated SF) is a genre of speculative fiction that deals with imaginative and futuristic concepts. These concepts may include information technology and robotics, biological manipulations, space ...

stories about the ''Flying-Fish'' airship-submarine, the ''Flying-Fish'' is hidden in Hurd's Deep between adventures.

Toponym

Geology

History

Deep sea ordnance disposal

Wrecks

In popular culture

Citations

Notes

References

Further reading