Hurd's Deep

Hurd's Deep (or Hurd Deep) is an underwater valley in the English Channel, northwest of the Channel Islands. Its maximum depth is about 180 m (590 ft; 98 fathoms), making it the deepest point in the English Channel.

Hurd Deep running from bottom left to top right of an extract from a 1955 Admiralty Chart
1955 Admiralty Chart No 2649 showing Hurd Deep in the context of the English Channel

Etymology

It is most probable the feature was named after Captain Thomas Hurd RN (1747–1823), by Admiral Martin White.[1]

Description

The feature has approximate dimensions of length of 150 km (93 mi); width of between 2 km (1.2 mi) and 5 km (3.1 mi) and maximum depth of 170 m (560 ft; 93 fathoms). It terminates abruptly at the western end. Outside of the deep the seafloor is typically flat with a depth range of 70 m (230 ft; 38 fathoms) to 90 m (300 ft; 49 fathoms).[2] It is the deepest point on the English channel.[3]

Late Quaternary origin

The underwater valley system found on the floor of the eastern English Channel formed from a catastrophic flood which was caused by a breaching of a rock dam at the Strait of Dover, which released a huge proglacial lake in the southern North Sea basin. The flood scoured the former river systems to form Hurd's Deep in late Quaternary times.[4][5]

Pleistocene glacial refugium

During the ice ages, when the sea level dropped, most of the English Channel was dry land. Hurd's Deep likely remained as a sea. During the Pleistocene it is thought to have been a glacial refugium.[6]

Seabed

Dumping

Following the First World War, Hurd's Deep was used by the British Government as a dumping ground for both chemical and conventional munitions.[7] SMS Baden was scuttled there in 1921.[8] 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.[9] Routine dumping of British munitions carried on until 1974.[7][10][lower-alpha 1]

Between 1946 and 1973 the area was also used for the dumping of low and intermediate level radioactive wastes. 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.[11][12]

Shipwrecks

The British submarine HMS Affray sank in Hurd's Deep in 1951 with the loss of 75 lives.[13]

In Harry Collingwood's science fiction stories about the Flying-Fish airship-submarine, the Flying-Fish is hidden in Hurd's Deep between adventures.[lower-alpha 2]

Notes, references and sources

Notes
  1. Admiralty Chart No 2649 English Channel Western Portion of 1955 shows munitions have been dumped there but cannot confirm further details
  2. The three stories are:
    • The Log of the ‘Flying Fish’: A Story of Aerial and Submarine Peril and Adventure (1887)
    • With Airship and Submarine: A Tale of Adventure (1907)
    • The Cruise of the 'Flying-Fish': The Airship-Submarine (1924)

References
  1. Davies, Martin (1973). "Martin White RN". La Société Jersiaise. The Island Wiki. Archived from the original on 27 February 2019. Retrieved 3 March 2019.
  2. Lericolais, G.; Guennoc, P.; Auffret, J. P.; Bourillet, J. F.; Berne, S. (7 October 1996). "Detailed survey of the western end of the Hurd Deep (English Channel): new facts for a tectonic origin". In De Batist, M.; Jacobs, P. (eds.). Geology of Siliciclastic Shelf Seas. Geological Society. ISBN 978-1897799710.
  3. Oggioni (2013), p. 42.
  4. Smith, Alec J. (1985). "A catastrophic origin for the palaeovalley system of the eastern English Channel". Marine Geology. 64 (1–2): 65–75. Bibcode:1985MGeol..64...65S. doi:10.1016/0025-3227(85)90160-4.
  5. Gupta, Sanjeev; Collier, Jenny S.; Palmer-Felgate, Andy; Potter, Graeme (2007). "Catastrophic flooding origin of shelf valley systems in the English Channel". Nature. 448 (7151): 342–345. Bibcode:2007Natur.448..342G. doi:10.1038/nature06018. PMID 17637667.
  6. Provan, Jim; Bennett, K.D. (2008). "Phylogeographic insights into cryptic glacial refugia". Trends in Ecology and Evolution. 23 (10): 564–571. doi:10.1016/j.tree.2008.06.010. PMID 18722689.
  7. Replacement Metallic Return Conductors - Marine Environmental Report (PDF) (Report). 4. Moyle Interconnector Ltd. December 2014. pp. D3–D4. Archived (PDF) from the original on 16 August 2019. Retrieved 16 August 2019.
  8. Schleihauf, p. 81.
  9. Carr, Gilly (7 March 2014). Legacies of Occupation: Heritage, Memory and Archaeology in the Channel Islands. p. 30. ISBN 978-3319034065.
  10. "Alderney Hurd Deep radioactive waste 'not dangerous'". BBC. 18 April 2013. Archived from the original on 13 February 2016. Retrieved 15 August 2019.
  11. Nuclear dumping leak sparks concern Archived 11 March 2006 at the Wayback Machine – BBC, 17 January 2002
  12. "Thousands of radioactive waste barrels rusting". Greenpeace. 19 June 2000. Archived from the original on 28 June 2009.
  13. "1951: Fears for crew of lost British submarine". Archived from the original on 7 March 2008. Retrieved 31 December 2007.

Sources
  • Schleihauf, William (2007). "The Baden Trials". In Preston, Anthony (ed.). Warship 2007. Annapolis: Naval Institute Press. ISBN 978-1-84486-041-8.


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