The
Celtic Sea ( ; ; ; ; ) is the area of the Atlantic Ocean
off the south coast of Ireland
.
It is
bounded to the east by Saint
George's Channel, the Bristol Channel
and the English Channel
, as well as adjacent portions of Wales
, Cornwall
, Devon
, and
Brittany. The southern and western
boundaries are based on the
continental shelf.
History
The
Celtic heritage of the bounding lands gives
the sea its name, first proposed by
E. W. L. Holt at a 1921 meeting in Dublin
of fisheries
experts from England, Ireland, Scotland and France.
The
northern portion of this sea had previously been considered as part
of Saint George's Channel and
the southern portion as an undifferentiated part of the "Southwest
Approaches
" to Great Britain. The need for a common
name came to be felt because of common
marine biology,
geology and
hydrology. It
was adopted in France before being common in the English-speaking
countries. It was adopted by marine biologists and oceanographers,
and later by oil exploration firms. It is named in a 1963 British
atlas, ; cited in
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."
Limits
There are no land features to divide the Celtic Sea from the open
Atlantic Ocean to the south and west.
For these limits, Holt
suggested the 200 fathom (366 m)
marine contour and Ushant
.
The
definition approved by 1974 by the Hydrographer of the Royal
Navy for use in Admiralty Charts was
"bounded roughly by lines joining Ushant, Land's End
, Hartland
Point
, Lundy
Island
, St. Govan's Head
and Rosslare, thence following the Irish
coast south to Mizen
Head
and then along the 200-metre isobath to approximately the latitude of
Ushant."
The
International
Hydrographic Organization definition, adopted by 1976, uses
rhumb lines and extends slightly further
south. It is as follows:
- Separated from the Irish Sea
to the north by a line from Carnsore Point, County Wexford
to Saint David's Head, Pembrokeshire
( )
- Along the Pembrokeshire coast
- Separated from the Bristol Channel
to the east by a line from Saint Govan's Head,
Pembrokeshire ( ) to Hartland Point
, Devon
- Separated from the English
Channel
to the east by a line from Land's End
, Cornwall to ÃŽle
Vierge, Finistère
( )
- Along the Finistère coast
- Separated from the Bay of Biscay
to the east by a line from Point
Penmarc'h
towards Cabo
Ortegal in Galicia
- From latitude 46°30’N on this line, northwestwards to
- From there north to
- From
there to Mizen
Head
, County
Cork
- Along
the Cork, Waterford
, and Wexford coasts to Carnsore Point.
Seabed
The seabed under the Celtic Sea is called the
Celtic
Shelf, part of the
continental shelf of
Europe. The northeast portion is c.90–100m deep,
increasing towards Saint George's Channel. In the opposite
direction, sand ridges pointing southwest have a similar height,
separated by troughs c.50m deeper. These ridges were formed by
tidal effects when the sea level was lower. South of 50° the
topography is more irregular.
See also
References
External links