Øresund, more commonly known in English as the Sound (Danish: Øresund, pronounced [ˈøːɐsɔnˀ]; Swedish: Öresund, pronounced [œrəˈsɵnːd]) and locally in both countries even known as just Sundet, is the strait that separates the Danish island Zealand from the southern Swedish province of Scania. Its width is just 4 kilometres (2.5 mi) at the narrowest point between Kronborg Castle at Helsingør in Denmark, and the northern harbour of Helsingborg in Scania, Sweden. The strait has also lent its name to the Øresund Region of 3.8 million inhabitants on both the Danish and Swedish sides.
The Øresund Bridge (which includes a 3 km tunnel) between the Danish capital Copenhagen and the largest city of Scania, Malmö, was inaugurated on 1 July 2000 by Queen Margrethe II of Denmark and King Carl XVI Gustaf of Sweden. Ferries run around the clock between Helsingborg, Sweden, and Helsingør, Denmark.
It is first attested on a Danish runestone from about 950, where it is written ura suti, i.e. Ø̄rasundi (in the dative). The West Norse and Icelandic form is Eyrarsund. The first part of the word is øre, Old Norse eyra, which means gravel beach, and the second part is sund, i.e. strait or narrow seaway. The strait is today called Øresund in Danish and Öresund in Swedish, informally Sundet (lit. "the Strait") in both languages.
Streams, animals and salinity
Øresund, like the other Danish and Danish-German straight, being at the border between oceanic salt water (which has a salinity of more than 30 PSU). As Cattegat in the north almost has oceanic conditions and the Baltic sea (only 6–7 PSU, in its main bassin) has brackish water, Øresund's water conditions are rather unique. 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, conditions are more stable and salinity is always oceanic (> 30 PSU) below a certain depth that varies between 10 and 15 metres. In the southern part, however, the depth is just 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. In the central Baltic Sea only 52 known salt-water species resided compare with 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 burning jellyfish (Cyanea Article); the latter can sometimes drift into the southwest Baltic sea, but it cannot reproduce there.
The daily tides exists, 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 different water levels in Øresund comes down to daily tides. And other circumstances "hides" the little tide that still remains. The current have a much stronger affect on the water level, compared to the tide. But stong winds may also affect the water level. During exceptional conditions, such as storms and hurricanes oceanic water may suddenly flow on all depths into the Baltic Sea. Such events gives deeps in southern Baltic Sea new fresh water, with higher salinity. This makes it possible for especially cod to breed in the Baltic Sea. If no such inflow of oceanic water to the Baltic Sea occurs for around a decade, the breeding of cod becomes endangered.
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 just 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. 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.
- Amager (western part is artificial enlargement from Øresund, or from Kalvebodene more precicely)
- Ven (also spelled Hven)
- Peberholm - an artificial island
- Middelgrundsfortet - an artificial island
- Flakfortet - an artificial island
- Gråen - an artificial island outside port of Landskrona (enlargements from Øresund in the 17th and 20th Centuries)
- "Bælthavet og Sundet" (in Danish). Danish Meteorological Institute. Retrieved 30 March 2013.
- 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."
- Danmarks runeindskrifter no. 117.
- Ordbog over det danske Sprog
- 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.
|Wikimedia Commons has media related to Oresund.|
- 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 (English) (Swedish) (Danish)