Hurd's Deep

The feature was named after the British Royal Naval Captain Thomas Hurd (1747–1823), who was the second Hydrographer of the Navy. It was chosen by the RN marine cartographer Admiral Martin White.{{cite journal|url=https://www.theislandwiki.org/index.php/Martin_White_RN|title=Martin White RN|journal=La Société Jersiaise|first=Martin|last=Davies|date=1973|access-date=3 March 2019|url-status=live|archive-url=https://web.archive.org/web/20190227221412/https://www.theislandwiki.org/index.php/Martin_White_RN|archive-date=27 February 2019|df=dmy-all|publisher=The Island Wiki}}

Hurd's deep began to form in the Pleistocene of the late Quaternary period (in the last 750,000 - 500,000 years). Successive melting periods after ice ages 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 basin created Hurd's Deep. It's believed that the collapse of a chalk ridge that once dammed the Strait of Dover let flood waters from a huge proglacial lake flow through the former river systems scouring down to the bedrock forming the trench.{{cite journal|last1=Smith|first1=Alec J.|title=A catastrophic origin for the palaeovalley system of the eastern English Channel|journal=Marine Geology|date=1985|volume=64|issue=1–2|pages=65–75|doi=10.1016/0025-3227(85)90160-4|bibcode=1985MGeol..64...65S}}{{cite journal|last1=Gupta|first1=Sanjeev|last2=Collier|first2=Jenny S.|last3=Palmer-Felgate|first3=Andy|last4=Potter|first4=Graeme|title=Catastrophic flooding origin of shelf valley systems in the English Channel|journal=Nature|date=2007|volume=448|issue=7151|pages=342–345|doi=10.1038/nature06018|pmid=17637667|bibcode=2007Natur.448..342G|s2cid=4408290 }}

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.{{cite journal|last1=Provan|first1=Jim|last2=Bennett|first2=K.D.|title=Phylogeographic insights into cryptic glacial refugia|journal=Trends in Ecology and Evolution|date=2008|volume=23|issue=10|pages=564–571|doi=10.1016/j.tree.2008.06.010|pmid=18722689}}

Hurd's Deep has an approximate length of {{Convert|150|km|nmi|round=5|abbr=off}} with a width of between {{Convert|2|and|5|km|nmi|frac=2|abbr=on}}. It terminates abruptly at the western end. The seafloor around the trench

is typically flat with a depth range of {{convert|70-90|m|ft fathom|-1|abbr=on}}. But within the trench the maximum depth is {{convert|170|m|ft fathom|abbr=on}}.{{cite book|title=Geology of Siliciclastic Shelf Seas|editor1=De Batist, M. |editor2=Jacobs, P.|publisher=Geological Society|issue=117|date=7 October 1996|chapter=Detailed survey of the western end of the Hurd Deep (English Channel): new facts for a tectonic origin|last1=Lericolais|first1=G.|last2=Guennoc|first2=P.|last3=Auffret|first3=J. P.|last4=Bourillet|first4=J. F.|last5=Berne|first5=S.|isbn=978-1897799710}} Hurd's Deep is the deepest point in the English Channel.{{Sfnp|Oggioni|2013|p=42}}

Following the First World War, Hurd's Deep was used by the British Government as a dumping ground for both chemical and conventional munitions.{{cite report|url=http://www.mutual-energy.com/downloads/moyle-repair-project/er-vol4.pdf|date=December 2014|title=Replacement Metallic Return Conductors - Marine Environmental Report|access-date=16 August 2019|pages=D3–D4|volume=4|url-status=live|archive-url=https://web.archive.org/web/20190816073956/http://www.mutual-energy.com/downloads/moyle-repair-project/er-vol4.pdf|archive-date=16 August 2019|df=dmy-all|publisher=Moyle Interconnector Ltd}} 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.{{cite book|title=Legacies of Occupation: Heritage, Memory and Archaeology in the Channel Islands|first=Gilly|last=Carr|page=30|date=7 March 2014|isbn=978-3319034065|author-link=Gillian Carr}} Routine dumping of British munitions carried on until 1974.{{cite news|url=https://www.bbc.co.uk/news/world-europe-guernsey-22198566|title=Alderney Hurd Deep radioactive waste 'not dangerous'|access-date=15 August 2019|date=18 April 2013|website=BBC|url-status=live|archive-url=https://web.archive.org/web/20160213232035/https://www.bbc.co.uk/news/world-europe-guernsey-22198566|archive-date=13 February 2016|df=dmy-all}}{{efn|Admiralty Chart No 2649 English Channel Western Portion of 1955 shows munitions have been dumped there but cannot confirm further details}}

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.[http://news.bbc.co.uk/1/hi/sci/tech/1766365.stm Nuclear dumping leak sparks concern] {{Webarchive|url=https://web.archive.org/web/20060311052309/http://news.bbc.co.uk/1/hi/sci/tech/1766365.stm |date=11 March 2006 }} – BBC, 17 January 2002{{cite web|url=http://www.greenpeace.org.uk/media/press-releases/thousands-of-radioactive-waste-barrels-rusting-away-on-the-seabed|title=Thousands of radioactive waste barrels rusting|website=Greenpeace|archive-url=https://web.archive.org/web/20090628103243/http://www.greenpeace.org.uk/media/press-releases/thousands-of-radioactive-waste-barrels-rusting-away-on-the-seabed|archive-date=28 June 2009|url-status=dead|date=19 June 2000|df=dmy-all}}

{{SMS|Baden}} was scuttled there in 1921.{{sfn|Schleihauf|p=81}} The British submarine {{HMS|Affray|P421|6}} sank in Hurd's Deep in 1951 with the loss of 75 lives.{{Cite news |url=http://news.bbc.co.uk/onthisday/hi/dates/stories/april/17/newsid_2847000/2847935.stm |title=1951: Fears for crew of lost British submarine |date=17 April 1951 |access-date=31 December 2007 |archive-url=https://web.archive.org/web/20080307120444/http://news.bbc.co.uk/onthisday/hi/dates/stories/april/17/newsid_2847000/2847935.stm |archive-date=7 March 2008 |url-status=live }}

In Harry Collingwood's science fiction stories about the Flying-Fish airship-submarine, the Flying-Fish is hidden in Hurd's Deep between adventures.{{efn|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)

}}

{{Notelist}}

{{Reflist}}

• {{Cite thesis|last=Oggioni|first=Francesa|date=2013|title=Characterization of catastrophic flood-related features in the English Channel

|type=Phd|publisher=Imperial College|location=London|url=https://core.ac.uk/download/pdf/76991047.pdf|url-status=live

|archive-url=https://web.archive.org/web/20200618100640/https://core.ac.uk/download/pdf/76991047.pdf

|archive-date=18 June 2020}}

• {{cite book

| last = Schleihauf

| first = William

| year = 2007

| chapter = The Baden Trials

| title = Warship 2007

| editor-last = Preston

| editor-first = Antony

| publisher = Naval Institute Press

| location = Annapolis

| isbn = 978-1-84486-041-8

| ref = {{sfnRef|Schleihauf}}

}}

{{coord|49|30|N|3|34|W|type:waterbody_scale:7500000|display=title}}

Category:English Channel

Category:Radioactive waste repositories