Irish Sea

Irish Sea
Satellite image
Limits and ports: ◘ ferry port / ◘ freight only
Location	Britain and Ireland
Coordinates	53°28′10″N 5°08′29″W / 53.469448°N 5.141419°W / 53.469448; -5.141419
Type	Sea
River sources	Rivers that flow into the Irish Sea
Ocean/sea sources	Celtic Sea
Basin countries	United Kingdom; Republic of Ireland; Isle of Man
Max. width	200 kilometres (120 mi)
Surface area	46,007 km2 (17,763 sq mi)
Average depth	80–275 metres (262–902 ft)
Water volume	2,800 km3 (2.3×109 acre⋅ft)
Islands	Anglesey and Holy Island, Isle of Man and Calf of Man, Bardsey Island, Walney, Lambay, Ireland's Eye
Settlements	(see below)

The Irish Sea

Cardigan Bay in the south, and the waters to the east of the Isle of Man, are less than 50 m (160 ft) deep. With a total water volume of 2,430 km³ (580 cu mi) and a surface area of 47,000 km² (18,000 sq mi), 80% is to the west of the Isle of Man. The largest sandbanks are the Bahama and King William Banks to the east and north of the Isle of Man and the Kish Bank, Codling Bank, Arklow Bank and Blackwater Bank near the coast of Ireland. The Irish Sea, at its greatest width, is 200 km (120 mi) and narrows to 75 km (47 mi).^[9]

The International Hydrographic Organization defines the limits of the Irish Sea (with St George's Channel) as follows,

On the North. The Southern limit of the Inner Seas off the West Coast of Scotland, defined as a line joining the South extreme of the Mull of Galloway (54°38'N) in Scotland and Ballyquintin Point (54°20'N) in Northern Ireland.

On the South. A line joining St. David's Head in Wales (51°54′N 5°19′W / 51.900°N 5.317°W / 51.900; -5.317) to Carnsore Point in Ireland (52°10′N 6°22′W / 52.167°N 6.367°W / 52.167; -6.367).^[4]

The Irish Sea has undergone a series of dramatic changes over the last 20,000 years as the

Because Ireland has neither tunnel nor bridge to connect it with Great Britain, the vast majority of heavy goods trade is done by sea. Northern Ireland ports handle 10 million tonnes (9,800,000 long tons; 11,000,000 short tons) of goods trade with the rest of the United Kingdom annually; the ports in the Republic of Ireland handle 7.6 million tonnes (7,500,000 long tons; 8,400,000 short tons), representing 50% and 40% respectively of total trade by weight.

The

Ports in the Republic handle 3,600,000 travellers crossing the sea each year, amounting to 92% of all Irish Sea travel.[15]

Ferry connections from

"Irish Sea" is also the name of one of the BBC's Shipping Forecast areas defined by the coordinates:

• 54°50′N 05°05′W / 54.833°N 5.083°W / 54.833; -5.083
• 54°45′N 05°45′W / 54.750°N 5.750°W / 54.750; -5.750
• 52°30′N 06°15′W / 52.500°N 6.250°W / 52.500; -6.250
• 52°00′N 05°05′W / 52.000°N 5.083°W / 52.000; -5.083

Transport for Wales Rail, Iarnród Éireann, Irish Ferries, Stena Line, Northern Ireland Railways, Stena Line and ScotRail promote SailRail with through rail tickets for the train and the ferry.^[16]

The British ship LCT 326 sank in the Irish sea and was discovered in March 2020. In September 2021, the British Navy ship HMS Mercury was discovered; it sank in 1940. The British ship SS Mesaba was sunk by the Imperial German Navy U-118 in 1918 and discovered in 2022. ^[17] This ship is well known for sailing near the Titanic and for attempting to warn the Titanic about dangerous icebergs.

Oil and gas exploration

Caernarfon Bay Basin

The

The Cardigan Bay Basin forms a continuation into British waters of Ireland's North Celtic Sea Basin, which has two producing gas fields. The basin comprises a south-easterly deepening half-graben near the Welsh coastline, although its internal structure becomes increasingly complex towards the southwest. Permian to Triassic, syn-rift sediments within the basin are less than 3 km (1.9 mi) thick and are overlain by up to 4 km (2.5 mi) of Jurassic strata, and locally also by up to 2 km (1.2 mi) of Paleogene fluvio-deltaic sediments. The basin has a proven petroleum system, with potentially producible gas reserves at the Dragon discovery near the UK/ROI median line, and oil shows in a further three wells. The Cardigan Bay Basin contains multiple reservoir targets, which include the Lower Triassic (Sherwood Sandstone), Middle Jurassic shallow marine sandstones and limestone (Great Oolite), and Upper Jurassic fluvial sandstone, the reservoir for the Dragon discovery.

The most likely hydrocarbon source rocks are Early Jurassic marine mudstones. These are fully mature for oil generation in the west of the British sector and are mature for gas generation nearby in the Irish sector. Gas-prone, Westphalian pre-rift coal measures may also be present at depth locally. The Cardigan Bay Basin was subjected to two Tertiary phases of compressive uplift, whereas maximum burial that terminated primary hydrocarbon generation was probably around the end of the Cretaceous, or earlier if Cretaceous strata, now missing, were never deposited in the basin. Despite the Tertiary structuration, the Dragon discovery has proved that potentially commercial volumes of hydrocarbons were retained at least locally in Cardigan Bay. In addition to undrilled structural traps, the basin contains the untested potential for stratigraphic entrapment of hydrocarbons near synsedimentary faults, especially in the Middle Jurassic section.^[19][20]

Liverpool Bay

The Liverpool Bay Development is

• Douglas oil field
• Hamilton gas field
• Hamilton North gas field
• Hamilton East gas field
• Lennox oil and gas field

Oil is produced from the Lennox and Douglas fields. It is then treated at the Douglas Complex and piped 17 km (11 mi) to an oil storage barge ready for export by tankers. Gas is produced from the Hamilton, Hamilton North and Hamilton East reservoirs. After initial processing at the

The quality of the water in Liverpool Bay was historically contaminated by dumping of sewage sludge at sea[21] but this practice became illegal in December 1988 and no further sludge was deposited after that date.^[22]

East Irish Sea Basin

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With 210 billion cubic metres (7.5 trillion cubic feet) of natural gas and 176 million barrels (28,000,000 m³) of petroleum estimated by the field operators as initially recoverable

• Listed are the islands in the Irish Sea which are either at least one square kilometre in area, or which have a permanent population.
• Anglesey and Holy Island are included separately.

Environment

The most accessible and possibly the greatest

The open sea is a complex habitat in its own right. It exists in three spatial dimensions and also varies over time and tide. For example, where freshwater flows into the Irish Sea in river estuaries its influence can extend far offshore as the freshwater is lighter and "floats" on top of the much larger body of salt water until wind and temperature changes mix it in. Similarly, warmer water is less dense and seawater warmed in the inter-tidal zone may "float" on the colder offshore water. The amount of light penetrating the seawater also varies with depth and turbidity. This leads to differing populations of plankton in different parts of the sea and varying communities of animals that feed on these populations. However, increasing seasonal storminess leads to greater mixing of water and tends to break down these divisions, which are more apparent when the weather is calm for long periods.

Plankton includes bacteria, plants (

Diatoms and dinoflagellates dominate the phytoplankton. Although they are microscopic plants, diatoms have hard shells and dinoflagellates have little tails that propel them through the water. Phytoplankton populations in the Irish Sea have a spring "bloom" every April and May, when the seawater is generally at its greenest.

A colossal diversity of invertebrate species live in the Irish Sea and its surrounding coastline, ranging from flower-like fan-worms to predatory swimming crabs to large chameleon-like cuttlefish.^[27] Some of the most significant for other wildlife are the reef-building species like the inshore horse mussel of Strangford Lough, the inter-tidal honeycomb worm of Morecambe Bay, Cumbria and Lancashire, and the sub-tidal honeycomb worm of the Wicklow Reef. These build up large structures over many years and, in turn, provide surfaces, nooks and crannies where other marine animals and plants may become established and live out some or all of their lives.

There are quite regular records of live and stranded leatherback turtles in and around the Irish Sea. This species travels north to the waters off the

Analysis[37]^[38] of the distribution of radioactive contamination after discharge reveals that mean sea currents result in much of the more soluble elements such as caesium being flushed out of the Irish Sea through the North Channel about a year after discharge. Measurements of technetium concentrations post-1994 has produced estimated transit times to the North Channel of around six months with peak concentrations off the northeast Irish coast occurring 18–24 months after peak discharge. Less soluble elements such as plutonium are subject to much slower redistribution. Whilst concentrations have declined in line with the reduction in discharges they are markedly higher in the eastern Irish Sea compared to the western areas. The dispersal of these elements is closely associated with sediment activity, with muddy deposits on the seabed acting as sinks, soaking up an estimated 200 kg (440 lb) of plutonium.^[39] The highest concentration is found in the eastern Irish Sea in sediment banks lying parallel to the Cumbrian coast. This area acts as a significant source of wider contamination as radionuclides are dissolved once again. Studies have revealed that 80% of current seawater contamination by caesium is sourced from sediment banks, whilst plutonium levels in the western sediment banks between the Isle of Man and the Irish coast are being maintained by contamination redistributed from the eastern sediment banks.

The consumption of seafood harvested from the Irish Sea is the main pathway for exposure of humans to radioactivity.^[40] The environmental monitoring report for the period 2003 to 2005 published by the Radiological Protection Institute of Ireland (RPII) reported that in 2005 average quantities of radioactive contamination found in seafood ranged from less than 1 Bq/kg (12 pCi/lb) for fish to under 44 Bq/kg (540 pCi/lb) for mussels.^[41] Doses of man-made radioactivity received by the heaviest consumers of seafood in Ireland in 2005 was 1.10 μSv (0.000110 rem).^[42] This compares with a corresponding dosage of radioactivity naturally occurring in the seafood consumed by this group of 148 μSv (0.0148 rem) and a total average dosage in Ireland from all sources of 3,620 μSv (0.362 rem).^[43] In terms of risk to this group, heavy consumption of seafood generates a 1 in 18 million chance of causing cancer. The general risk of contracting cancer in Ireland is 1 in 522. In the UK, the heaviest seafood consumers in Cumbria received a radioactive dosage attributable to Sellafield discharges of 220 μSv (0.022 rem) in 2005.^[44] This compares to average annual dose of naturally sourced radiation received in the UK of 2,230 μSv (0.223 rem).^[45]

Proposed fixed sea link connections

Discussions of linking Britain to Ireland began in 1895,

An offshore wind farm was developed on the

Further wind turbine sites include:

• The
  NPower Renewables
• Burbo Bank site 10 kilometres (6.2 mi) off the north Wirral coast
• Robin Rigg Wind Farm in the Solway Firth
• Thirty 90-metre (300 ft) 3 MW turbines are operating in a wind farm 7 km (4.3 mi) the coast of Walney Island.^[55]
• Turbines are being erected off the coast of Clogherhead (to be called the Oriel Wind Farm)^[56]
• The Warmley Extension 14 kilometres (9 mi) west of Walney Island off the coast of Cumbria. As of 2018, it is the largest on Earth.^[57]

In popular culture

• During World War I the Irish Sea became known as "U-boat Alley", because the U-boats moved their emphasis from the Atlantic to the Irish Sea after the United States entered the war in 1917.^[58][59]
• The Port of Barrow-in-Furness, one of Britain's largest shipbuilding centres and home to the United Kingdom's only submarine-building complex, is only a minor port.
• The Irish Sea figures prominently in the
  Bendigeidfran, King of the Island of the Mighty. Branwen and Matholwch marry, but when she becomes abused by Matholwch, her brother crosses the sea from Wales to Ireland to rescue her. Within the story the Irish Sea is said to be shallow; in addition, it contains two rivers, the Lli and the Archan.^[60]
• The fictional
  Thomas and Friends based on Awdry's books, is located in the Irish Sea.^[61]

• List of crossings of the Irish Sea
• North Channel bridge proposal
• Transport in Ireland
• Transport in the United Kingdom
• Transport on the Isle of Man

Explanatory notes

References

Citations

1. ^ "Muir Éireann". téarma.ie – Dictionary of Irish Terms. Foras na Gaeilge and Dublin City University. Archived from the original on 10 May 2017. Retrieved 18 November 2016.
2. ^ "Ellan Vannin" (in Manx). Centre for Manx Studies ("Laare-Studeyrys Manninagh"). Archived from the original on 4 March 2011. Retrieved 8 July 2011.
3. ^ Cambridge Medieval Celtic Studies, Issues 33–35 University of Cambridge (Gran Bretaña). Department of Anglo-Saxon, Norse and Celtic 1997
4. ^ ^{a b} "Limits of Oceans and Seas, 3rd edition + corrections" (PDF). International Hydrographic Organization. 1971. p. 42 [corrections to page 12]. Archived from the original (PDF) on 8 October 2011. Retrieved 28 December 2020.
5. ^ Electronic Dictionary of the Irish Language
6. OCLC 725928669
   .
7. ^ "The Caledonian". The Caledonian. 4. New York: Caledonian Publishing Co.: 25 1903.
8. ^ "Irish Sea Facts". Irish Sea Conservation. Archived from the original on 11 May 2011. Retrieved 3 July 2011.
9. ^ M J Howarth. "Hydrography of the Irish Sea" (PDF). United Kingdom Department of Trade and Industry. Archived (PDF) from the original on 4 March 2016. Retrieved 2 February 2015.
10. ^ "DISCOVERING FOSSILS | How Great Britain formed". www.discoveringfossils.co.uk. Archived from the original on 1 October 2018. Retrieved 12 August 2019.
11. ^ ^{a b} "Ships and Boats: Prehistory to Present | Historic England". historicengland.org.uk. Archived from the original on 15 August 2019. Retrieved 15 August 2019.
12. ^ "Chapter 7: The Cambro-Norman Reaction: The Invasion of Ireland". vlib.iue.it. Archived from the original on 24 February 2019. Retrieved 12 August 2019.
13. ^ Port Statistics, (Link) Archived 24 September 2005 at the Wayback Machine, Mersey Docks Website
14. ^ UK Port Traffic Highlights: 2002, (pdf) Archived 8 November 2006 at the Wayback Machine, UK Maritime Statistics, Dept of Transport
15. Central Statistics Office of Ireland
16. ^ "SailRail". Irishrail.ie. Archived from the original on 8 February 2014. Retrieved 16 April 2015.
17. ^ "Titanic: Ship that sent iceberg warning found in Irish Sea". BBC News. 27 September 2022.
18. ^ "DTI Strategic Environmental Assessment Area 6, Irish Sea, seabed and surficial geology and processes" (PDF). British Geological Survey. 2005. Retrieved 7 April 2023.
19. ^ ^{a b} "Petroleum prospectivity of the princial sedimentary basin on the United Kingdom Continental Shelf" (PDF). United Kingdom: Department of Trade and Industry. Archived from the original (PDF) on 15 October 2005.
20. ^ "Liverpool Bay, England". BHP Oil Ltd. 7 May 2005. Archived from the original on 7 May 2005. Retrieved 7 April 2023.
21. ^ C.Michael Hogan. 2011. Irish Sea. eds. P.Saundry & C.Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC Archived 2 June 2013 at the Wayback Machine
22. ^ "Pollution: Liverpool Bay". www.parliament.uk. Archived from the original on 10 March 2018. Retrieved 1 September 2017.
23. ^ Population figures are from 2001 Census, except: Isle of Man, from 2006.
    Populations of smaller islands are estimated at 5 per known inhabited house
24. ^ Isle of Man Census 2006 Archived 17 January 2013 at the Wayback Machine (excluding the population of 2 living on the Calf of Man)
25. ^ National Statistics – Walney North (Ward) Archived 14 July 2014 at the Wayback Machine and Walney South (Ward) Archived 14 July 2014 at the Wayback Machine
26. ISBN 978-1-873701-87-4
27. ^
    ISBN 978-0-85323-227-8
28. ^ "Unravelling the secret lives of jellyfish using electronic tags". Irish Sea Leatherback Turtle Project. Archived from the original on 28 November 2008.
29. ^ "The INTERREG Irish Sea Leatherback Sea Turtle Project". Ecogel. Archived from the original on 9 August 2011.
30. ISBN 978-1-907390-37-1. Archived
    (PDF) from the original on 3 March 2016. Retrieved 3 January 2015.
31. ^ "Plan to bring grey whales back to Britain". The Telegraph. 18 July 2005. Archived from the original on 1 February 2014. Retrieved 26 November 2013.
32. ^ Sellafield nuclear reprocessing facility, Greenpeace Archived 3 March 2016 at the Wayback Machine
33. ^ ^{a b} The Past, Current and Future Radiological Impact of the Sellafield Marine Discharges on the People Living in the Coastal Communities Surrounding the Irish Sea, (Link) Archived 3 October 2008 at the Wayback Machine, Environment Agency – Table 3
34. ^
    British Nuclear Group
    – Table 2
35. ^ León Vintró et al. (2000), p. 2.
36. OSPAR
    – Chapter 4 Chemistry, p64
37. ^ León Vintró et al. (2000), sections 3–4.
38. ^ McMahon et al., 2005, (Link) Archived 30 September 2007 at the Wayback Machine, Transfer of conservative and non-conservative radionuclides from the Sellafield Nuclear Fuel Reprocessing plant to the coastal waters of Ireland
39. OSPAR
    – Chapter 4 Chemistry, p66
40. ^ Ryan et al. (2005), p. 7.
41. ^ Ryan et al. (2005), Table 45.
42. ^ Ryan et al. (2005), p. 26.
43. ^ Ryan et al. (2005), p. 27.
44. Cefas
    – p11
45. ^ Watson et al., 2005 (Link) Archived 7 March 2008 at the Wayback Machine, Health Protection Agency – Ionising Radiation Exposure of the UK Population: 2005 Review
46. ^ "TUNNEL UNDER THE SEA", The Washington Post, 2 May 1897 (Archive link) Archived 3 November 2012 at the Wayback Machine
47. ^ Boyd, Wesley (7 February 2004). "An Irishman's Diary". The Irish Times.
48. ^ Written Answers. – Sea Transport, (Link) Archived 12 March 2007 at the Wayback Machine, Dáil Éireann – Volume 384 – 16 November 1988
49. ^ Written Answers. – Irish Sea Railway Ferry, (Link) Archived 29 November 2007 at the Wayback Machine, Dáil Éireann – Volume 434 – 19 October 1993
50. ^ Written Answers. – Ireland-UK Tunnel, (Link), Dáil Éireann – Volume 517 – 29 March 2000
51. ^ Written Answers – Transport Projects, (Link), Dáil Éireann – Volume 597 – 15 February 2005
52. BBC News Scotland. 22 August 2007. Archived
    from the original on 1 July 2008. Retrieved 3 June 2023.
53. Airtricity. Archived from the original
    on 21 December 2007. Retrieved 9 December 2006.
54. ^ "Northhoyle". NPower Renewables. Archived from the original on 22 July 2005. Retrieved 11 August 2005.
55. ^ "Barrow Offshore windfarm". BOWind. Archived from the original on 8 July 2012. Retrieved 24 September 2019.
56. ^ "Oriel Wind project status". Oriel Windfarm. Archived from the original on 7 July 2008. Retrieved 7 October 2007.
57. ISSN 0261-3077. Archived
    from the original on 6 September 2018. Retrieved 3 June 2023.
58. ISBN 978-0-9549186-0-6
59. ^ The War in Maps: The Irish Sea, (Link) Archived 19 August 2005 at the Wayback Machine, UBoat.net
60. ^ Williams, Ifor. Pedeir Keinc y Mabinogi. University of Wales Press.
61. ^ "Where is Sodor, home of Thomas the Tank Engine?". BBC News Online. 4 July 2011. Retrieved 3 March 2016.

General sources

• Luis León Vintró; Kilian J. Smith; Julie A. Lucey; Peter I. Mitchell (4–6 December 2000). The environmental impact of the Sellafield discharges (PDF). SCOPE-RADSITE Workshop. Brussels.
• R. W. Ryan; A. Dowdall; M. F. Fegan; E. Hayden; K. Kelleher; S. Long; I. McEvoy; L. McKittrick; C. A. McMahon; M. Murray; K. Smith; S. Sequeira; J. Wong; D. Pollard. Radioactive Monitoring of the Irish Environment 2003–2005 (PDF). Radiological Protection Institute of Ireland. Archived from the original (PDF) on 27 March 2009.

Further reading

• Cowsill, Miles; Hislip, Gordon (2016). Ferries of the Irish Sea: across four decades. Ramsey, Isle of Man: Ferry Publications.
  ISBN 978-1-906608-64-4
  .
• Herdman, W. A.; Dawson, Robert A. (1902). Fishes and fisheries of the Irish Sea. London: George Philip & Son Ltd.

External links

Wikimedia Commons has media related to Irish Sea.

Look up irish sea in Wiktionary, the free dictionary.

• Fylde Coast Marine Life Project
• Irish Sea Conservation Zones
• The Wildlife Trusts Living Seas – Irish Sea