Irish Sea
Area of the Atlantic Ocean off the southern coast of Ireland.
Wikipedia / Wikimedia Commons
The Irish Sea is a body of water separating the islands of Ireland and Great Britain, connecting to the Celtic Sea via St George’s Channel to the south and to the Inner Seas off the West Coast of Scotland via the North Channel to the north. Its shores touch Scotland, England, Wales, Northern Ireland, and the Republic of Ireland. The largest island within the sea is Anglesey in North Wales, followed by the Isle of Man; the term Manx Sea is occasionally used. The sea is economically vital for regional trade, shipping, transport, fishing, and power generation from wind and nuclear plants, with over twelve million passengers and substantial volumes of traded goods crossing annually between Great Britain and Ireland. Geologically, the Irish Sea formed during the Neogene era. During the last glacial period, its central area was likely a freshwater lake, which reconnected to the sea as ice retreated about ten thousand years ago. The sea features a deeper western channel, roughly two hundred miles long and forty miles wide, with depths ranging from about forty to one hundred and fifty meters, while shallower bays to the east, such as Cardigan Bay and waters east of the Isle of Man, are less than fifty meters deep. Major sandbanks include the Bahama and King William Banks near the Isle of Man, and the Kish, Codling, Arklow, and Blackwater Banks off Ireland. The International Hydrographic Organization defines its northern limit from the Mull of Galloway in Scotland to Ballyquintin Point in Northern Ireland, and its southern limit from St David’s Head in Wales to Carnsore Point in Ireland. Historically, the Romans called it Mare Hibernicus, and it witnessed notable invasions, including the Norman invasion of Ireland in the late twelfth century and a Tudor invasion in 1529.
- surface_area
- 46,007 km² (17,763 sq mi)
- max_width
- 200 km (120 mi)
- min_width
- 75 km (47 mi)
- max_depth
- 275 m (900 ft)
- water_volume
- 2,430 km³ (580 cu mi)
- largest_island
- Anglesey, North Wales
- second_largest_island
- Isle of Man
Verified Timeline
Lore & Background
The Celtic Sea receives its name from the Celtic heritage of the bounding lands to the north and east. E. W. L. Holt proposed the name at a 1921 meeting of fisheries experts from Great Britain, France, and the Republic of Ireland in Dublin. This sea's northern portion was considered part of Saint George's Channel, and the southern portion was an undifferentiated part of the Southwest Approaches to Great Britain. The desire for a common name came to be felt because of the area's common marine biology, geology and hydrology. It was adopted in France before being common in English-speaking countries. In 1957, Édouard Le Danois wrote, "the name Celtic Sea is hardly known even to oceanographers." Marine biologists and oceanographers adopted it, and later, by petroleum exploration firms. It is named in a 1963 British atlas, but a 1972 article states, "what British maps call the Western Approaches, and what the oil industry calls the Celtic Sea [...] certainly the residents on the western coast [of Great Britain] don't refer to it as such."
Reader's Guide
The seabed under the Celtic Sea is referred to as the Celtic Shelf, part of the continental shelf of Europe. The northeast portion has a depth of between 90 and 100 m (300–330 ft), increasing towards Saint George's Channel. In the opposite direction, sand ridges pointing southwest have a similar height, separated by troughs approximately 50 m (160 ft) deeper. These ridges were formed by tidal effects when the sea level was lower. South of 50°N, the topography is more irregular. Oil and gas exploration in the Celtic Sea has had limited commercial success. The Kinsale Head gas field supplied much of Ireland's demand for gas in the 1980s and 1990s. The water is too deep for fixed wind turbines. The area has potential for 50 GW of floating wind farms, and TotalEnergies plans a project with almost 100 MW. The Celtic Sea has a rich fishery with total annual catches of 1.8 million tonnes as of 2007. Four cetacean species occur frequently: minke whale, bottlenose dolphin, short-beaked common dolphin and harbor porpoise. Formerly, it held an abundance of marine mammals.
Did You Know?
- E. W. L. Holt proposed the name 'Celtic Sea' at a 1921 meeting of fisheries experts from Great Britain, France, and the Republic of Ireland in Dublin.
- In 1957, Édouard Le Danois wrote that 'the name Celtic Sea is hardly known even to oceanographers.'
- The Kinsale Head gas field supplied much of Ireland's demand for gas in the 1980s and 1990s.
- The area has potential for 50 GW of floating wind farms, and TotalEnergies plans a project with almost 100 MW.
- Total annual fish catches in the Celtic Sea were 1.8 million tonnes as of 2007.
More in Seas And Oceans 1-24
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record