Last updated
Map of Oresund new version.JPG
Øresund, showing its northern and southern boundaries
Europe relief laea location map.jpg
Red pog.svg
Coordinates 55°45′N12°45′E / 55.750°N 12.750°E / 55.750; 12.750 Coordinates: 55°45′N12°45′E / 55.750°N 12.750°E / 55.750; 12.750
Type Strait
Basin  countries Sweden and Denmark
Max. length118 km (73 mi)
Max. width28 kilometres (17 mi)
Min. width4 km (2.5 mi)
Max. depth−40 m (−130 ft)
Denmark (Zealand) seen from the Swedish (Scania) side of Oresund Central Oresund from Scanian Side.jpg
Denmark (Zealand) seen from the Swedish (Scania) side of Øresund

Øresund or Öresund ( UK: /ˌɜːrəˈsʊnd/ , US: /ˈɜːrəsʌn,-sʊnd,ˈɔːrəsʊnd/ ; [1] [2] [3] Danish : Øresund [ˈøːɐˌsɔnˀ] ; Swedish : Öresund [œrɛˈsɵnːd] ), [4] commonly known in English as the Sound, [5] is a strait which forms the Danish–Swedish border, separating Zealand (Denmark) from Scania (Sweden). The strait has a length of 118 kilometres (73 mi) and the width varies from 4 kilometres (2.5 mi) to 28 kilometres (17 mi). It is 4 kilometres (2.5 mi) wide at its narrowest point between Helsingør in Denmark and Helsingborg in Sweden.


Øresund is along with the Great Belt, Little Belt and Kiel Canal one of four waterways that connects the Baltic Sea to the Atlantic Ocean via Kattegat, Skagerrak, and the North Sea, and is one of the busiest waterways in the world. [6]

The Øresund Bridge, between the Danish capital Copenhagen and the Swedish city of Malmö, inaugurated on 1 July 2000, connects a bi-national metropolitan area with close to 4 million inhabitants. [7] The HH Ferry route, between Helsingør, Denmark and Helsingborg, Sweden, in the northern part of Øresund, is one of the world's busiest international ferry routes with more than 70 departures from each harbour per day. [8]

Øresund is a geologically young strait that formed 8500–8000 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 by the Great Belt. As such the entrance of salt water by Øresund marked the beginning of the modern Baltic Sea as a salt-water sea. [9]


The strait is called Øresund in Danish and Öresund in Swedish, informally Sundet [10] (lit. "the Strait") in both 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 /øːrasundi/ (the dative case). [11] The Old West Norse (and modern Icelandic) form of the name is Eyrarsund. Ör 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 many place names along the strait e.g. Helsingør, Skanör, Dragør and Halör, an important center of trade during the Viking Age. [10] [12] [13]


The northern boundary between Øresund and Kattegat is a line which goes from Gilleleje at Zealand's northern peak to the westernmost point of Kullaberg (Kullen's Lighthouse) at the smaller peninsula north of Helsingborg, known as Kullahalvön. In the south, the boundary towards the Baltic Sea 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 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 by weight) and the far less salty Baltic Sea.

As the Kattegat 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 North Sea. 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 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 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.

Generally, when the current shifts from northbound to southbound, it never turns 180 degrees with the same flow, instead does the current "slow down to zero" and then begins to flow in opposite direction. (Local phenomenon close to shores, might differ from this general pattern)

Kronborg castle is situated on the extreme northeastern tip of the island of Zealand at the narrowest point of the Oresund Helsingor Kronborg slot IMG 6985 ID dk 217-70554-1.JPG
Kronborg castle is situated on the extreme northeastern tip of the island of Zealand at the narrowest point of the Øresund
Northern Oresund Oresund from helsingborg.jpg
Northern Øresund


Political control of Øresund has been an important issue in Danish and Swedish history. Denmark maintained military control with the coastal fortress of Kronborg at Elsinore on the west side and Kärnan at Helsingborg on the east, until the eastern shore was ceded to Sweden in 1658, based on the Treaty of Roskilde. 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.

To be independent of the Øresund, Sweden carried out two great projects, the foundation of Göteborg (Gothenborg) 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



Oresund Strait from Malmo Oresund Panorama.jpg
Øresund Strait from Malmö

Notable bights



See also

Related Research Articles

Baltic Sea Sea in Northern Europe

The Baltic Sea is a mediterranean sea of the Atlantic Ocean, enclosed by Denmark, Estonia, Finland, Latvia, Lithuania, Sweden, northeast Germany, Poland, Russia and the North and Central European Plain.

Helsingør Place in Capital, Denmark

Helsingør, classically known in English as Elsinore, is a city in eastern Denmark. Helsingør Municipality had a population of 62,686 on 1 January 2018. Helsingør and Helsingborg in Sweden together form the northern reaches of the Øresund Region, centered on Copenhagen and Malmö. The HH Ferry route connects Helsingør with Helsingborg, 4 km across the Øresund.

Kattegat sea area between Denmark and Sweden

The Kattegat is a 30,000 km2 (12,000 sq mi) sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark to the south and the provinces of Västergötland, Scania, Halland and Bohuslän in Sweden in the east. The Baltic Sea drains into the Kattegat through the Danish Straits. The sea area is a continuation of the Skagerrak and may be seen as a bay of the Baltic Sea or the North Sea or, as in traditional Scandinavian usage, neither of these.

Zealand Largest and most populous island in Denmark proper

Zealand, at 7,031 km2, is the largest and most populous island in Denmark proper. Zealand has a population of 2,302,074.

Øresund Bridge road and railway bridge over Øresund

The Öresund or Øresund Bridge is a combined railway and motorway bridge across the Öresund strait between Sweden and Denmark. The bridge runs nearly 8 kilometres from the Swedish coast to the artificial island Peberholm in the middle of the strait. The crossing is completed by the 4-kilometre (2.5 mi) Drogden Tunnel from Peberholm to the Danish island of Amager.

Tårnby Municipality Municipality in Capital Region, Denmark

Tårnby Kommune is a municipality bordering Copenhagen Municipality on the island of Amager just south of Zealand (Sjælland) in eastern Denmark. The municipality includes the islands of Saltholm and Peberholm, and covers an area of 65 km². It has a population of 43,010. Its mayor is Allan S. Andersen, a member of the Social Democrats (Socialdemokraterne) political party.

Amager island in the Øresund

Amager in the Øresund is Denmark's most densely populated island, with almost 200,000 inhabitants on the small appendix to Zealand. The protected natural area of Naturpark Amager makes up more than one-third of the island's total area of 96 km2.

Skagerrak Sea between Denmark, Norway and Sweden

The Skagerrak is a strait running between the southeast coast of Norway, the west coast of Sweden, and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.

Great Belt Strait in Denmark linking the Baltic Sea to the Kattegat strait and the Atlantic Ocean

The Great Belt is a strait between the major islands of Zealand (Sjælland) and Funen (Fyn) in Denmark. It is one of the three Danish Straits.

Helsingborg Place in Scania, Sweden

Helsingborg is a town and the seat of Helsingborg Municipality, Scania, Sweden. It had 108,334 inhabitants in 2017. Helsingborg is the centre of the northern part of western Scania and Sweden's closest point to Denmark: the Danish city Helsingør is clearly visible about 4 km (2 mi) to the west on the other side of the Øresund. The HH Ferry route across the sound has more than 70 car ferry departures from each harbour every day.

European route E47 road in Europe

European route E47 is a road connecting Lübeck in Germany to Helsingborg in Sweden via the Danish capital, Copenhagen. It is also known as the Vogelfluglinie and the Sydmotorvej. The road is of motorway standard all the way except for 28 km (17 mi) in Germany and 6 km of city roads in Helsingør; there are also two ferry connections. A fixed link between Germany and Denmark was planned to have been completed by the year 2020; however, the Danish parliament has decided that a tunnel would be safer and greener than a bridge. Although a bridge-tunnel combination has been constructed between Denmark and Sweden further south, a very frequent ferry service continues to operate between Helsingør in Denmark and the northern terminus of the E47 at Helsingborg in Sweden.

Capital Region of Denmark Region of Denmark in Copenhagen

The Capital Region of Denmark is the easternmost administrative region of Denmark, established on January 1, 2007 as part of the 2007 Danish Municipal Reform, which abolished the traditional counties and set up five regions. At the same time, smaller municipalities were merged into larger units, cutting the number of municipalities from 271 before 1 January 2006, when Ærø Municipality was created, to 98. The Capital Region has 29 municipalities. The regional council consists of 41 elected politicians. The chairman as of 1 January 2014 is Sophie Hæstorp Andersen. She is a member of the Social Democrats political party. The reform was implemented on January 1, 2007. The main task for the Danish regions are hospitals and healthcare. It is not to be confused with the Copenhagen Metropolitan Area nor with the Øresund Region. Unlike the counties (1970-2006) the regions are not municipalities and are thus not allowed to have coat of arms, but only logotypes, and cannot "shuffle money around" from one area of expenditure to another area of expenditure, that is, use money for any other purpose than has been stated specifically, but must pay money not used back rather like departments or agencies of the central government. The regions do not levy any taxes but are financed only through block grants.

Helsingør Municipality municipality in the Capital Region of Denmark

Helsingør Municipality, is a municipality in the Capital Region on the northeast coast of the island of Zealand (Sjælland) in eastern Denmark. The municipality covers an area of 122 km², and has a total population of 61,538. Its mayor as of 1 January 2014 is Benedikte Kiær, a member of the Conservative political party.

Danish straits three channels in Denmark connecting the Baltic Sea to the North Sea

The Danish straits are the straits connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. Historically, the Danish straits were internal waterways of Denmark; however, following territorial losses, Øresund and Fehmarn Belt are now shared with Sweden and Germany, while the Great Belt and the Little Belt have remained Danish territorial waters. The Copenhagen Convention of 1857 made all the Danish straits an international waterway.

Sound Dues tariff

The Sound Dues were a toll on the use of the Øresund which constituted up to two thirds of Denmark's state income in the 16th and 17th centuries. The dues were introduced by King Eric of Pomerania in 1429 and remained in effect until the Copenhagen Convention of 1857.

Amager Strandpark park in Copenhagen Municipality, Denmark

Amager Strandpark is a seaside public park in Copenhagen, Denmark. It is located on the island of Amager and includes an artificial island and offers a total of 4.6 km (2.9 mi) of beaches. From the beach, the Middelgrunden wind farm can be seen on the horizon.

Helsingør–Helsingborg ferry route Denmark–Sweden ferry route

The Helsingør–Helsingborg ferry route is a shipping route connecting Helsingør (Elsinore), Denmark and Helsingborg, Sweden across the northern, and narrowest part of the Øresund. Due to the short distance, which is less than 3 nautical miles, is it one of the world's busiest international car ferry routes, with around 70 daily departures from each harbour. The oldest-known written mention of the route dates to the German traveller Adam of Bremen in the 11th century, but it has likely been in use much longer. Before 1658, the route was a domestic Danish route. For several centuries, the route has been run regularly by various Danish shipping lines. Its significance grew during the 1950s, but since the inauguration of the Øresund Bridge in 2000, at the southern end of the Øresund, it has lost some significance but remains as one of the world's most important ferry routes, particularly as a cheaper alternative to the bridge tolls. Since 1952, passports have not been required for Scandinavian and Finnish citizens.

Denmark–Sweden border international border between Denmark and Sweden

The current national border between Denmark and Sweden dates to 1658.

Køge Bugt bay in Denmark

Køge Bugt or Køge Bay is an approximately 500 km2-shallow Danish bay in the southern part of Øresund, between Greater Copenhagen area in the North and Stevns Klint in the South, and as a part of Zealand. It is name after the Danish town Køge, which is located towards its southern part. The area around the bay's shores are built-up from Copenhagen to Køge, including Copenhagen suburban areas like Brøndby Strand, Vallensbæk, Ishøj, Hundige, Jersie and others. The seafloor is not located deeper than 10 meters anywhere inside the bay. Due to its closeness to the Baltic Sea, the average surface salinity is lower than elsewhere in Øresund, especially when compared to the northern parts of this sound.



  1. "Øresund" (US) and "Øresund". Oxford Dictionaries . Oxford University Press . Retrieved February 6, 2019.
  2. "Øresund". Merriam-Webster Dictionary . Retrieved February 6, 2019.
  3. "Øresund". The American Heritage Dictionary of the English Language (5th ed.). Boston: Houghton Mifflin Harcourt. 2014. Retrieved February 6, 2019.
  4. "Bælthavet og Sundet" (in Danish). Danish Meteorological Institute . Retrieved 30 March 2013.
  5. "The Sound." Encyclopædia Britannica. 12 March 2004. Retrieved 20 April 2017.
  6. Gluver, Henrik; Dan Olsen (1998). "2.7 Øresund Bridge, Denmark-Sweden". Ship Collision Analysis. Rotterdam: A. A. Balkema. ISBN   90-5410-962-9. Øresund (the Strait) is, like the Great Belt, an important water way for the international ship traffic between the North Sea and the Baltic Sea.
  7. The region has a population of 3,894,365 (2015) and a population density of 187/km². "Geography". Tendens Øresund. Retrieved 29 October 2010.. On 1 January 2016 the name of the region was changed to "Greater Copenhagen and Skåne" by the Øresund Committee.
  8. "At Scandlines". press "Tidtabell 2 jan-31 maj 2015", PDF file.
  9. Björck, Svante; Andrén, Thomas; Jensen, Jørn Bo (2008). "An attempt to resolve the partly conflicting data and ideas on the ancylus-Littorina transition". Proceedings of the Workshop "Relative sea level changes". Polish Geological Institute Special Papers. 23. pp. 21–26.
  10. 1 2 "141-142 (Nordisk familjebok / Uggleupplagan. 34. Ö - Öyslebö; supplement: Aa - Cambon)". runeberg.org (in Swedish). 1922. Retrieved 2017-10-17.
  11. Mejlbystenen, DR 117. ᛬ᛁ᛬ᚢᚱᛅ᛬ᛋᚢᛏᛁ᛬ "in the ear-sound".
  12. Øre Ordbog over det danske Sprog "et smalt stykke land imellem to store vande, fra et land til andet. [...] Øresund kaldes saaledes fordi det begynder ved Siellands Øre og ved Øster-Søen ved et Øre, som er Skan-Øre. [...] sandet ell. gruset strand(bred), ofte spec.: dannende en odde, en halvø ell. en smal landtange." Katlev, Jan (2000). Politikens Etymologisk Ordbog. Copenhagen: Politikens Forlag. p. 694. ISBN   87-567-6200-3. af ør, øre 'gruset strandbred' + sund. Ør, Ordbog over det danske Sprog . C.f. also Ole Lauridsen in the Danish radio program Sproghjørnet (audio clip in Danish).
  13. 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’"