- Øresund (Oresund);
- Storebælt (Great Belt); and,
- Lillebælt (Little Belt).
Oresund is the eastern-most of the Danish Straits, separating the Danish island of Zealand (Sjaelland in Danish) from the Swedish mainland.
Denmark and Sweden were linked in prehistoric times—until 7000 years ago when rising sea levels accompanying the end of the Ice Age severed the dry-land connection between the two.
At its narrowest, between Helsingor'/Elsinor (Demark) and Helsingborg (Sweden), the Oresund is approximately 2.5 miles (4 kilometres). A ferry connects the two sides, but the construction of a tunnel is under consideration.
The 16-kilometre-long Oresund Link between Malmo, Sweden (right), and Copenhagen, Denmark (left), was completed and opened to traffic in 2000.
The Oresund Link has three main segments.
On the Denmark side, the link begins with a 3510-metre (2.2-mile) underwater tunnel.
The tunnel emerges from the water onto a roadway on a 4055-metre (2.5-mile) artificial island, Peberholm, which appears as a bright white shape to the south of the natural island in the scene below.
The cable-supported Oresund Bridge stretches 7845 metres (4.9 miles) across the eastern part of the Strait toward Sweden, producing a thin white line across the image.
Storebælt (Great Belt)
Storebælt (Great Belt) is the middle and widest strait of the three main Danish Straits. It passes between between the main islands of Zealand (Sjælland) and Funen (Fyn). Being the widest, it is the main channel for vessels passing between the Baltic Sea and the North Sea.
The Great Belt is sometimes viewed in two parts: a "northern zone" between Zealand and Funen (The Great Belt proper); and, a "southern zone" between the islands of Langeland and Lolland (a strait called Langelandsbaelt).
The Great Belt is crossed by the Great Belt Bridge (Great Belt Fixed Link) which connects a point just south of Korsor on the island of Zealand to Nyborg on the island of Funen
As shown in the images right and below, the mid point of the bridge is the island of Sprogø.
A suspension bridge (4.2 miles, 6.8 km "East Bridge") carries a road from Korsor to Sprogø, while two connected tunnels convey the rail link. The suspension bridge has the world's third longest main span: 5328 feet or 1624 m, under which the main shipping lanes pass.
A "box girder" bridge (4.2 miles, 6.6 km "West Bridge") connects Sprogø to south of Nyborg. This bridge has two separate spans, one for rail and one for road traffic. The Link openned in 1998.
Lillebælt (Little Belt)
Lillebælt (Little Belt) is the western most and narrowest of the straits. As such it is not generally used by larger vessels.
The strait is at its narrowest (just 800 metres) between the island of Funen (Fyn) and the mainland of Denmark (Jutland), where it crossed by two bridges:
- the "Old Little Belt Bridge" (3865 feet, or 1.2 km) originally serving rail, road and pedestrians, but now carrying just a rail link; and,
- the new "Little Belt Bridge" (1.1 mile, or 1.7 km), a suspension road bridge.
The Danish Straits are becoming an increasingly important route for Russian oil exports to Europe and is an oil transit chokepoint.
About three million barrels per day (bbl/d) flowed through this waterway in 2010, with most of this product moving westward. Russia has increasingly been shifting its crude oil exports to its Baltic ports, especially the relatively new port of Primorsk, which accounted for half of the exports through the Straits. An estimated 0.3 million bbl/d of crude oil, primarily from Norway, flowed eastward to Scandinavian markets.
About one-third of the westward exports through the Straits are for refined products, coming from Baltic Sea ports such as Tallinn (Muuga), Venstpils, and St. Petersburg.