Firth is a word in the
English and
Scots languages used to denote various coastal waters in the
United Kingdom, predominantly within
Scotland. In the
Northern Isles, it more often refers to a smaller
inlet. It is linguistically
cognate to fjord (both from
Proto-Germanic *ferþuz), which has a more constrained sense in English. Bodies of water named "firths" tend to be more common on the Scottish east coast, or in the southwest of the country, although the
Firth of Clyde is an exception to this. The
Highland coast contains numerous estuaries, straits, and inlets of a similar kind, but not called "firth" (e.g.
the Minch and
Loch Torridon); instead, these are often called
sea lochs. Before about 1850, the spelling "Frith" was more common.
A firth is generally the result of
ice ageglaciation and is very often associated with a large river, where erosion caused by the tidal effects of incoming sea water passing upriver has widened the riverbed into an
estuary. Demarcation can be rather vague. The
Firth of Clyde is sometimes thought to include the estuary as far upriver as
Dumbarton, but the
Ordnance Survey map shows the change from river to firth occurring off
Port Glasgow. In navigation terms, the dredged River Clyde Channel for shipping meets the Firth of Clyde Channel at the
Tail of the Bank, where the river crosses a
sandbar off
Greenock as the estuary widens at the junction to the
Gare Loch. Locally, the river can be described as extending even further west to
Gourock point.
However, some firths are exceptions. The
Cromarty Firth on the east coast of Scotland, for example, resembles a large
loch with only a relatively small outlet to the sea and the
Solway Firth and the
Moray Firth are more like extremely large bays. The
Pentland Firth is a
strait rather than a bay or an inlet.
Scottish firths
Firths on the west coast of Scotland (from north to south)
In
Scottish Gaelic, the Firth of Clyde is treated as two bodies, with the landward end being called Linne Chluaidh (IPA:[ˈʎiɲəˈxl̪ˠuəj]; meaning the same as the English), while the area around the south of Arran, Kintyre and Ayrshire/
Galloway is An Linne GhlasScottish Gaelic pronunciation:[əˈʎiɲəˈɣl̪ˠas̪].
The Northern Isles were part of Norway until the 15th century, and retain many Norse names. In Shetland in particular, "firth" can refer to smaller inlets, although geo, voe and wick are as common. In Orkney, "wick" is common.
Likewise, in the
Northern Isles, the words "firth" and "sound" are often used arbitrarily or interchangeably.
Bluemull Sound for example, is very similar to some of the firths in the
Shetland Islands.
^Anderson, Joseph (Ed.) (1893) Orkneyinga Saga. Translated by Jón A. Hjaltalin & Gilbert Goudie. Edinburgh. James Thin and Mercat Press (1990 reprint).
ISBN0-901824-25-9