Strait
A strait is a water body connecting two seas or water basins. The surface water is, for the most part, at the same elevation on both sides and can flow through the strait in either direction, although the topography generally constricts the flow somewhat. In some straits, there is a dominant directional current. Most commonly, the strait is a narrow channel that lies between two land masses. Straits are loci for sediment accumulation, with sand-sized deposits usually occurring on the two strait exits, forming subaqueous fans or deltas. Some straits are not navigable because they are too narrow, too shallow, or due to the presence of a reef or archipelago.
Terminology
The terms channel, pass, or passage can be synonymous and used interchangeably with strait, although each is sometimes differentiated with varying senses. In Scotland, firth or Kyle are also sometimes used as synonyms for strait.Many straits are economically important. Straits can be important shipping routes and wars have been fought for control of them.
Numerous artificial channels, called canals, have been constructed to connect two oceans or seas over land, such as the Suez Canal. Although rivers and canals often provide passage between two large lakes, and these seem to suit the formal definition of strait, they are not usually referred to as such. Rivers and often canals, generally have a directional flow tied to changes in elevation, whereas straits often are free flowing in either direction or switch direction, maintaining the same elevation. The term strait is typically reserved for much larger, wider features of the marine environment. There are exceptions, with straits being called canals; Pearse Canal, for example.
Comparisons
Straits are the converse of isthmuses. That is, while a strait lies between two land masses and connects two large areas of ocean, an isthmus lies between two areas of ocean and connects two large land masses.Some straits have the potential to generate significant tidal power using tidal stream turbines. Tides are more predictable than wave power or wind power. The Pentland Firth may be capable of generating 10 GW. Cook Strait in New Zealand may be capable of generating 5.6 GW even though the total energy available in the flow is 15 GW.