Øresund or Öresund (, ; ; ), commonly known in English as the Sound, is a strait which forms the Danish–Swedish border, separating

Zealand Zealand ( ) is the largest and most populous islands of Denmark, island in Denmark proper (thus excluding Greenland and Disko Island, which are larger in size) at 7,031 km2 (2715 sq. mi.). Zealand had a population of 2,319,705 on 1 Januar ...

(

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

) from

Scania Scania ( ), also known by its native name of Skåne (), is the southernmost of the historical provinces of Sweden, provinces () of Sweden. Located in the south tip of the geographical region of Götaland, the province is roughly conterminous w ...

(

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

). The strait has a length of ; its width varies from to . The narrowest point is between Helsingør in Denmark and

Helsingborg Helsingborg (, , ), is a Urban areas in Sweden, city and the seat of Helsingborg Municipality, Scania County, Scania (Skåne), Sweden. It is the second-largest city in Scania (after Malmö) and List of urban areas in Sweden by population, ninth ...

in Sweden. Øresund, along with the Great Belt, the

Little Belt The Little Belt (, ) is a strait between the island of Funen and the Jutland Peninsula in Denmark. It is one of the three Danish straits, Danish Straits that drain and connect the Baltic Sea to the Kattegat strait, which drains west to the Nor ...

and the

Kiel Canal The Kiel Canal (, until 1948 called in German the ) is a fresh water canal that links the North Sea () to the Baltic Sea (). It runs through the Germany, German states of Germany, state of Schleswig-Holstein, from Brunsbüttel to the Holtenau di ...

, is one of four waterways that connect the

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 ...

to the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

via

Kattegat The Kattegat (; ; ) is a sea area bounded by the peninsula of Jutland in the west, the Danish straits islands of Denmark and the Baltic Sea to the south and the Swedish provinces of Bohuslän, Västergötland, Halland and Scania in Swede ...

Skagerrak The Skagerrak (; , , ) is a strait running between the North Jutlandic Island of Denmark, the east coast of Norway and the west coast of Sweden, connecting the North Sea and the Kattegat sea. The Skagerrak contains some of the busiest shipping ...

, 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 ...

; this makes it one of the busiest waterways in the world. The Øresund Bridge, between the Danish capital

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

and the Swedish city of

Malmö Malmö is the List of urban areas in Sweden by population, third-largest city in Sweden, after Stockholm and Gothenburg, and the List of urban areas in the Nordic countries, sixth-largest city in Nordic countries, the Nordic region. Located on ...

, inaugurated on 1 July 2000, connects a bi-national

metropolitan area A metropolitan area or metro is a region consisting of a densely populated urban area, urban agglomeration and its surrounding territories which share Industry (economics), industries, commercial areas, Transport infrastructure, transport network ...

with close to 4 million inhabitants. The HH Ferry route, between Helsingør, Denmark and

, Sweden, in the northern part of Øresund, is one of the world's busiest international

ferry 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 ...

routes, with more than 70 departures from each harbour per day. Øresund is a geologically young strait that formed 8,500–8,000 years ago as a result of rising sea levels. Previously, the Ancylus Lake, a fresh-water body occupying the Baltic basin, had been connected to the sea solely via the Great Belt. The incursion of salt water via Øresund marked the beginning of the modern Baltic Sea as a salt-water body.

Name

The strait is called ''Øresund'' in Danish (and Norwegian), and ''Öresund'' in Swedish, informally ''Sundet'' () in all three languages. The first part of the name is '' øre'' "gravel/sand beach", and the second part is '' sund'', i.e. "sound, strait". The name is first attested on a runestone dated to ca. AD 1000, where it is written as ''ura suti'', read as

Old East Norse Old East Norse was a dialect of Old Norse which evolved into the languages of Old Danish and Old Swedish from the 9th century to the 12th century. Between 800 and 1100, East Norse is in Sweden called '' Runic Swedish'' and in Denmark ''Runic ...

(the dative case). The Old West Norse (and

modern Icelandic Icelandic ( ; , ) is a North Germanic language from the Indo-European language family spoken by about 314,000 people, the vast majority of whom live in Iceland, where it is the national language. Since it is a West Scandinavian language, it ...

) form of the name is ''Eyrarsund''. ''Ør'' is the modern form of the old Norse word (aur) meaning a gravel beach or shoal (see also ayre), often forming a spit. Such landforms are common in the area and "ör" is found in the names of many places along the strait, e.g. Helsingør, Skanör, Dragør and Halör, an important center of trade during the

Viking Age The Viking Age (about ) was the period during the Middle Ages when Norsemen known as Vikings undertook large-scale raiding, colonising, conquest, and trading throughout Europe and reached North America. The Viking Age applies not only to their ...

. ''Svensk Ordbok''
published by the Swedish Academy "Ör: (bank av) grus eller sand ..sedan 1000-talet runsten, Funbo, Uppland (Sveriges runinskrifter) runform aur, fornsv. ör, sv. dial. ör ’grus, sten’"

Boundaries

The northern boundary between Øresund and

is a line which goes from

Gilleleje Gilleleje () is a fishing town and seaside resort on the north coast of the peninsula North Zealand, Denmark. The town is located at the northernmost point of the island of Zealand. It is one of the main towns of the Gribskov municipality in Regio ...

at Zealand's northern peak to the westernmost point of Kullaberg (Kullen's Lighthouse) at the smaller peninsula north of

, known as Kullahalvön. In the south, the boundary towards the

starts at Stevns Klint, at the westernmost peak of the peninsula just south of Køge Bay, Stevns Peninsula to Falsterbo at the Falsterbo peninsula. Its eastern boundary is the Swedish coastline; to the west

Amager Amager ( ), located in the Øresund, is Denmark's most densely populated island, with more than 216,000 inhabitants (January 2022). The protected natural area of ''Naturpark Amager'' (including Kalvebod Fælled) makes up more than one-third of the ...

may be considered part of Øresund (in which case it is the largest island) or a part of Zealand. Amager has eight connections with Zealand (two street bridges, a road bridge, a motorway bridge, a dual-track railway tunnel, an underground metro and a bicycle bridge) as well as a combined motorway and dual track railway to Scania and Sweden.

Streams, animals and salinity

Øresund, like other Danish and Danish-German straits, is at the border between oceanic salt water (which has a salinity of more than 30 PSU or

per mille The phrase per mille () indicates parts per thousand. The associated symbol is , similar to a per cent sign but with an extra zero in the division (mathematics), divisor. Major dictionaries do not agree on the spelling, giving other options o ...

by weight) and the far less salty

. As the

in the north has almost oceanic conditions and the Baltic Sea (around 7 PSU, in its main basin) has brackish water, Øresund's water conditions are rather unusual and shifting. The streams are very complex, but the surface stream is often northbound (from the Baltic Sea) which gives a lower surface salinity, though streams can change from one day to another. The average surface salinity is about 10–12 PSU in the southern part, but above 20 PSU north of Helsingør. Near the seafloor (where the sea is deep enough), conditions are more stable and salinity is always oceanic (above 30 PSU) below a certain depth that varies between 10 and 15 metres. In the southern part, however, the depth is 5–6 metres (outside the rather narrow waterways Drogden and Flintrännan), and this is the definite border of oceanic salt water, therefore also a border for many maritime species of animals. Only 52 known salt-water species reside in the central Baltic Sea, compared to around 1500 in the

. Close to 600 species are known to exist in at least some part of Øresund. Well-known examples, for which the bottom salinity makes a distinct breeding border, include lobster, small crabs ('' Carcinus maenas''), several species of

flatfish A flatfish is a member of the Ray-finned fish, ray-finned demersal fish Order (biology), suborder Pleuronectoidei, also called the Heterosomata. In many species, both eyes lie on one side of the head, one or the other migrating through or around ...

and the lion's mane jellyfish; the latter can sometimes drift into the southwest Baltic Sea, but it cannot reproduce there. There are daily tides, but the lunar attraction cannot force much water to move from west to east, or vice versa, in narrow waters where the current is either northbound or southbound. So, not much of the difference in water levels in Øresund is due to daily tides, and other circumstances "hide" the little tide that still remains. The current has a much stronger effect than the tide on the water level, but strong winds may also affect the water level. During exceptional conditions, such as storms and hurricanes, oceanic water may suddenly flow into the Baltic Sea at all depths. Such events give deep waters in the southern Baltic Sea higher salinity, which makes it possible for

cod Cod (: cod) is the common name for the demersal fish genus ''Gadus'', belonging to the family (biology), family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus ''Gad ...

to breed there. If no such inflow of oceanic water to the Baltic Sea occurs for around a decade, the breeding of cod becomes endangered. KronborgCastleDenmarkOct152022 07

History

Political control of Øresund has been an important issue in Danish and Swedish history. Denmark maintained

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a d ...

control with the

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

fortress A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from L ...

of Kronborg at Elsinore on the west side and Kärnan at

on the east, until the eastern shore was ceded to Sweden in 1658, based on the

Treaty of Roskilde The Treaty of Roskilde was negotiated at Høje Taastrup Church and was concluded on 26 February ( OS) or 8 March 1658 ( NS) during the Second Northern War between Frederick III of Denmark–Norway and Karl X Gustav of Sweden in the Danish ci ...

. Both fortresses are located where the strait is 4 kilometres wide. In 1429, King Eric of Pomerania introduced the Sound Dues which remained in effect for more than four centuries, until 1857. Transitory dues on the use of waterways, roads, bridges and crossings were then an accepted way of taxing which could constitute a great part of a state's income. The Strait Dues remained the most important source of income for the Danish Crown for several centuries, thus making Danish kings relatively independent of Denmark's privy council and

aristocracy Aristocracy (; ) is a form of government that places power in the hands of a small, privileged ruling class, the aristocracy (class), aristocrats. Across Europe, the aristocracy exercised immense Economy, economic, Politics, political, and soc ...

. To be independent of the Øresund, Sweden carried out two great projects: the foundation of

Gothenburg Gothenburg ( ; ) is the List of urban areas in Sweden by population, second-largest city in Sweden, after the capital Stockholm, and the fifth-largest in the Nordic countries. Situated by the Kattegat on the west coast of Sweden, it is the gub ...

in 1621 and the construction of the Göta Canal from 1810 to 1832. The Copenhagen Convention of 1857 abolished the Dues and made the Danish straits an international waterway. A fixed connection was opened across the strait in 2000, the Øresund Bridge.

Notable islands

Denmark

(western part is artificial enlargement from Øresund, or from Kalvebodene more precisely) * Saltholm * Peberholm – an

artificial island An artificial island or man-made island is an island that has been Construction, constructed by humans rather than formed through natural processes. Other definitions may suggest that artificial islands are lands with the characteristics of hum ...

* Middelgrundsfortet – an

* Flakfortet – an

* Amager Strandpark - an artificial beach area for Copenhagen * Brøndby Strandpark - an artificial beach area for Copenhagen in Køge Bugt * Vallensbæk-Ishøj Strandpark - an artificial beach area for Copenhagen in Køge Bugt

Sweden

* Ven (Hven in older Swedish and Danish) * Gråen – an artificial island outside port of Landskrona (enlargements from Øresund in the 17th and 20th centuries)

Notable sights

Denmark

* Køge Bugt (Køge Bay) * Nivå Bugt (Nivå Bay) * Kalveboderne

Sweden

* Lundåkrabukten (Lundåkra Bay) * Lommabukten (Lomma Bay) * Höllviken ORESUNDBRIDGE_WIDE

References

Notes

Bibliography

* Menefee, Samuel Pyeatt, "The Strait Dues and Access to the Baltic Sea" in Renate Platzoder and Philomene Verlaan (eds.), ''The Baltic Sea: New Developments in National Policies and International Co-Operation '' (1996), pp. 101–32.

External links

Øresunddirekt
– Official public information site for the inhabitants of the Øresund region
Øresund Trends
– An official public information site with up-to-date information on the region, available in English
Øresundstid
– The History of the Øresund Region {{DEFAULTSORT:Oresund Straits of the Baltic Sea Straits of Denmark Straits of Sweden Geography of Copenhagen Landforms of Skåne County International straits Seas of Denmark Kronborg

Name

Boundaries

Streams, animals and salinity

History

Notable islands

Denmark

Sweden

Notable sights

Denmark

Sweden

See also

References

Notes

Bibliography

External links