The Strait of Dover or Dover Strait, historically known as the Dover Narrows, is the

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 flows through the strait in both directions, even though the topography generally constricts the ...

at the narrowest part of the

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

, marking the boundary between the Channel and the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

, and separating

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

from

continental Europe Continental Europe or mainland Europe is the contiguous mainland of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mean the whole of Europe – and, by som ...

. The shortest distance across the strait, at approximately , is from the South Foreland, northeast of

Dover Dover ( ) is a town and major ferry port in Kent, southeast England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies southeast of Canterbury and east of Maidstone. ...

in the English county of

Kent Kent is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Essex across the Thames Estuary to the north, the Strait of Dover to the south-east, East Sussex to the south-west, Surrey to the west, and Gr ...

, to Cap Gris Nez, a cape near to

Calais Calais ( , , traditionally , ) is a French port city in the Pas-de-Calais department, of which it is a subprefecture. Calais is the largest city in Pas-de-Calais. The population of the city proper is 67,544; that of the urban area is 144,6 ...

in the French

département In the administrative divisions of France, the department (, ) is one of the three levels of government under the national level (" territorial collectivities"), between the administrative regions and the communes. There are a total of 101 ...

Pas-de-Calais The Pas-de-Calais (, ' strait of Calais'; ; ) is a department in northern France named after the French designation of the Strait of Dover, which it borders. It has the most communes of all the departments of France, with 890, and is the ...

. Between these points lies the most popular route for cross-channel swimmers. The entire strait is within the

territorial waters Territorial waters are informally an area of water where a sovereign state has jurisdiction, including internal waters, the territorial sea, the contiguous zone, the exclusive economic zone, and potentially the extended continental shelf ( ...

of France and the United Kingdom, but a right of

transit passage Transit passage is a concept of the law of the sea, which allows a vessel or aircraft the freedom of navigation or overflight solely for the purpose of continuous and expeditious transit of a strait between one part of the high seas or exclusive ...

under the

United Nations Convention on the Law of the Sea The United Nations Convention on the Law of the Sea (UNCLOS), also called the Law of the Sea Convention or the Law of the Sea Treaty, is an international treaty that establishes a legal framework for all marine and maritime activities. , 169 sov ...

allows vessels of other nations to move freely through the strait. On a clear day, it is possible to see the opposite coastline of England from France and vice versa with the naked eye, with the most famous and obvious sight being the

White Cliffs of Dover The White Cliffs of Dover are the region of English coastline facing the Strait of Dover and France. The cliff face, which reaches a height of , owes its striking appearance to its composition of chalk accented by streaks of black flint, depo ...

from the French coastline and shoreline buildings on both coastlines, as well as lights on either coastline at night, as in

Matthew Arnold Matthew Arnold (24 December 1822 – 15 April 1888) was an English poet and cultural critic. He was the son of Thomas Arnold, the headmaster of Rugby School, and brother to both Tom Arnold (academic), Tom Arnold, literary professor, and Willi ...

's poem " Dover Beach".

Shipping traffic

Most maritime traffic between the Atlantic Ocean and the North Sea and

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

passes through the Strait of Dover, rather than taking the longer and more dangerous route around the north of Scotland. The strait is one of the busiest international seaways in the world, used by over 400 commercial vessels daily. This has made traffic safety a critical issue, with HM Coastguard and the

Maritime Gendarmerie The Maritime Gendarmerie () is a component of the French National Gendarmerie under operational control of the chief of staff of the French Navy. It employs 1,157 personnel and operates around thirty patrol boats and high-speed motorboats distri ...

maintaining a 24-hour watch over the strait and enforcing a strict regime of shipping lanes. In addition to the intensive north-east to south-west traffic, the strait is crossed from north-west to south-east by

ferries A ferry is a boat or ship that transports passengers, and occasionally vehicles and cargo, across a body of water. A small passenger ferry with multiple stops, like those in Venice, Italy, is sometimes referred to as a water taxi or water bus. ...

linking

and

Dunkirk Dunkirk ( ; ; ; Picard language, Picard: ''Dunkèke''; ; or ) is a major port city in the Departments of France, department of Nord (French department), Nord in northern France. It lies from the Belgium, Belgian border. It has the third-larg ...

. Until 1994 these provided the only route across it except for air transport. The

Channel Tunnel The Channel Tunnel (), sometimes referred to by the Portmanteau, portmanteau Chunnel, is a undersea railway tunnel, opened in 1994, that connects Folkestone (Kent, England) with Coquelles (Pas-de-Calais, France) beneath the English Channel at ...

now provides an alternative route, crossing beneath the strait at an average depth of below the seabed. The town of Dover gives its name to one of the sea areas of the British

Shipping Forecast The ''Shipping Forecast'' is a BBC Radio broadcast of weather reports and forecasts for the seas around the British Isles. It is produced by the Met Office and broadcast by BBC Radio 4 on behalf of the Maritime and Coastguard Agency. The for ...

Geological formation

The formation of strait was through scouring by

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

. It had for many millennia (since the last warm

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene i ...

) been a land bridge that linked the

Weald The Weald () is an area of South East England between the parallel chalk escarpments of the North and the South Downs. It crosses the counties of Hampshire, Surrey, West Sussex, East Sussex, and Kent. It has three parts, the sandstone "High W ...

in Great Britain to the Boulonnais in the

Pas de Calais The Strait of Dover or Dover Strait, historically known as the Dover Narrows, is the strait at the narrowest part of the English Channel, marking the boundary between the Channel and the North Sea, and separating Great Britain from continental ...

. Though pitted by troughs and rivers, the English Channel was almost mainly land at the height of the last ice age. The predominant geology of both and of the seafloor is

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...

. Although somewhat resistant to erosion, erosion of both coasts has created the famous

white cliffs of Dover The White Cliffs of Dover are the region of English coastline facing the Strait of Dover and France. The cliff face, which reaches a height of , owes its striking appearance to its composition of chalk accented by streaks of black flint, depo ...

in the UK and the Cap Blanc Nez in France. The

was bored through solid chalk – compacted remains of sea creatures and marine- deposited, ground up calciferous rock/soil debris. The

Rhine The Rhine ( ) is one of the List of rivers of Europe, major rivers in Europe. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps. It forms part of the Swiss-Liechtenstein border, then part of the Austria–Swit ...

(as the

Urstrom The Urstrom is a geologists' name for a great glacial age river of the Polish and north German plain, which drained the combined melt-waters from the northern headwaters of the Alps and the southern part of the Scandinavian ice during the Devens ...

) flows northeast into the North Sea as the sea (covering most of the Netherlands) fell during the start of the first of the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Ice Ages An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and Gre ...

. The new ice unusually created a dam from

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

to Scotland, and the Rhine, combined with the

Thames The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after th ...

and drainage from much of

north Europe The northern region of Europe has several definitions. A restrictive definition may describe northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54th parallel north, 54°N, or may be based on other ge ...

, created a vast lake behind the dam, which eventually spilled over the Weald into the English Channel. This overflow followed by further scouring became recognisably the Short Straits (an alternative name for this strait) about 425,000 years ago. A narrow deep channel along the middle of the strait is the remnants of the main (summer) outflow of the northern Ustrom glacial lake (a collect for other then-seasonal rivers, in winter iced up, such as the Thames and Weser) in the last Ice Age. A deposit in

East Anglia East Anglia is an area of the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire, with parts of Essex sometimes also included. The name derives from the Anglo-Saxon kingdom of the East Angles, ...

marks the old preglacial northward course of the Urstrom-Thames when it also drained Doggerland. The deep sea floor east of

Lincolnshire Lincolnshire (), abbreviated ''Lincs'', is a Ceremonial counties of England, ceremonial county in the East Midlands and Yorkshire and the Humber regions of England. It is bordered by the East Riding of Yorkshire across the Humber estuary to th ...

and East Yorkshire, connecting to the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

via the

Pentland Firth The Pentland Firth (, meaning the Orcadian Strait) is a strait which separates the Orkney Islands from Caithness in the north of Scotland. Despite the name, it is not a firth. Etymology The name is presumed to be a corruption of the Old Nors ...

in the last glaciation (of over 300,000 years) is a condition for the relatively late cutting through of the Strait to the south. Strait of Dover MODIS

A 2007 study concluded that the Strait was formed by erosion caused by two major floods. The first was about 425,000 years ago, when an ice-dammed lake in the southern North Sea overflowed and broke the Weald-

Artois Artois ( , ; ; Picard: ''Artoé;'' English adjective: ''Artesian'') is a region of northern France. Its territory covers an area of about 4,000 km2 and it has a population of about one million. Its principal cities include Arras (Dutch: ...

(Boulonnais) chalk range in a catastrophic erosion and flood event. Consequently the ice-age-muted flows from the Thames and

Scheldt The Scheldt ( ; ; ) is a river that flows through northern France, western Belgium, and the southwestern part of Netherlands, the Netherlands, with its mouth at the North Sea. Its name is derived from an adjective corresponding to Old Englis ...

flowed through the gap into the English Channel/Inlet, but the

Meuse The Meuse or Maas is a major European river, rising in France and flowing through Belgium and the Netherlands before draining into the North Sea from the Rhine–Meuse–Scheldt delta. It has a total length of . History From 1301, the upper ...

and Rhine still flowed without any significant link to the inlet (such as today's

IJssel The IJssel (; ) is a Dutch distributary of the river Rhine that flows northward and ultimately discharges into the IJsselmeer (before the 1932 completion of the Afsluitdijk known as the Zuiderzee), a North Sea natural harbour. It more immediatel ...

distributary supports). In a second flood about 225,000 years ago supported by glaciers extending from areas then land such as the

Zuiderzee The Zuiderzee or Zuider Zee (; old spelling ''Zuyderzee'' or ''Zuyder Zee''), historically called Lake Almere and Lake Flevo, was a shallow bay of the North Sea in the northwest of the Netherlands. It extended about 100 km (60 miles) inla ...

, the Meuse and Rhine were ice-dammed into a lake that broke catastrophically through a high weak barrier (perhaps chalk, or an end-moraine left by the ice sheet). Both floods cut massive flood channels in the dry bed of the English Channel, somewhat like the

Channeled Scablands The Channeled Scablands are a relatively barren and soil-free region of interconnected relict and dry flood channels, coulees and cataracts eroded into Palouse loess and the typically flat-lying basalt flows that remain after cataclysmic floods ...

or the

Wabash River The Wabash River () is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed May 13, 2011 river that drains most of the state of Indiana, and a significant part of Illinois, in the United ...

in the USA. A further update in 2017 attributed underwater holes in the Channel floor, "100 m deep" and in places "several kilometres in diameter", to lake water plunging over a rock ridge causing isolated depressions or

plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or Shut-in (river), shut-in. It is created by the erosion, erosional forces of cascading water on the rocks at the formation's bas ...

s. The melting ice and rising sea levels submerged Doggerland, the area linking Britain to France, around 6,500–6,200 BCE. The Lobourg strait, the deepest part the strait, runs its wide slash on a NNE–SSW axis. Nearer to the French coast than to the English, it borders the Varne sandbank (shoals) where it plunges to and further south, the Ridge bank (shoals) (French name "''Colbart''") with a maximum depth of .

Marine wildlife

The depth of the strait varies between at the Lobourg strait and at the highest banks. The seabed forms successions of three habitats: *rocky zones relatively deserted by ships wanting to spare their nets *sandy flats * sub-aqueous dunes. The strong tidal currents of the strait at depth slow around its rocky masses as these stimulate countercurrents and deep, calm pockets where many species can find shelter. In these calmer lee zones, the water is clearer than in the rest of the strait; thus

alga Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...

e can grow despite the average depth. They help increase diversity in the local species – some of which are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the strait. Moreover, this is a transition zone for the species of the Atlantic Ocean and those of the southern part of the North Sea. This mix of various environments promotes a wide variety of wildlife. The '' Ridens de Boulogne'', a deep rocky shoal, partially sand-capped, west of

Boulogne Boulogne-sur-Mer (; ; ; or ''Bononia''), often called just Boulogne (, ), is a coastal city in Hauts-de-France, Northern France. It is a Subprefectures in France, sub-prefecture of the Departments of France, department of Pas-de-Calais. Boul ...

, boasts the highest profusion of maerl in the strait. Thus some of the strait is classified as a

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectiv ...

protection zone named '' Ridens et dunes hydrauliques du Pas de Calais'' (Ridens and sub-aqueous dunes of the Dover Strait). This includes the sub-aqueous dunes of Varne, Colbart, Vergoyer and Bassurelle, the ''Ridens de Boulogne'', and the Lobourg channel which provides calmer and clearer waters due to its depth reaching .

Unusual crossings

Many crossings other than in conventional vessels have been attempted, including by

pedalo A pedalo (British English), pedal boat (U.S. English), or paddle boat (U.S., Canadian, and Australian English) is a human-powered watercraft propelled by the action of bicycle pedal, pedals turning a paddle wheel. Description A pedalo is ...

, jetpack,

bathtub A bathtub, also known simply as a bath or tub, is a container for holding water in which a person or another animal may Bathing, bathe. Most modern bathtubs are made of thermoformed Acrylic resin, acrylic, porcelain enamel, porcelain-enameled s ...

amphibious vehicle An amphibious vehicle (or simply amphibian) is a vehicle that works both on land and on or under water. Amphibious vehicles include amphibious Amphibious cycle, bicycles, Amphibious ATV, ATVs, Amphibious automobile, cars, Duckboats, buses, truc ...

and more commonly by

swimming Swimming is the self-propulsion of a person through water, such as saltwater or freshwater environments, usually for recreation, sport, exercise, or survival. Swimmers achieve locomotion by coordinating limb and body movements to achieve hydrody ...

. Since

French law French law has a dual jurisdictional system comprising private law (), also known as judicial law, and public law (). Judicial law includes, in particular: * () * Criminal law () Public law includes, in particular: * Administrative law ( ...

bans many of them, unlike

English law English law is the common law list of national legal systems, legal system of England and Wales, comprising mainly English criminal law, criminal law and Civil law (common law), civil law, each branch having its own Courts of England and Wales, ...

, most such crossings originate in England.

Ice

In the late 17th century during the "

Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Mat ...

", there were reports of severe winter ice in the English Channel and Strait of Dover, including a case in 1684 of only a league of open water remaining between Dover and Calais.

Notes

References

External links

Channel Navigation Information Service

Channel Swimming & Piloting Federation

Channel Swimming Association

Depth Chart showing straits and former course of Rhine
{{Authority control Straits of England Landforms of Kent Port of Dover, Kent English Channel France–United Kingdom border International straits Straits of Metropolitan France Landforms of Hauts-de-France