Great Belt

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

Effectively dividing Denmark in two, the Belt was served by the Great Belt ferries from the late 19th century until the islands were connected by the Great Belt Fixed Link in 1997–98.

The Great Belt is the largest and most important of the three Danish Straits that connect the Baltic Sea to the Kattegat strait and Atlantic Ocean. The others are the Øresund and the Little Belt straits.

The Great Belt is 60 km (37 miles) long and 16–32 km (10–20 miles) wide. It flows around two major islands: Samsø in the north and Langeland to the south. At Sprogø the Great Belt divides into the East Channel and the West Channel. Both are traversed by the Great Belt Bridge, but a tunnel also runs under the East Channel.

In pre-glacial times a river, which the Baltic Sea basin then contained and which geologists call the Eridanos, must have passed through the region. So also did the Eemian Sea, just prior to the last glaciation, which covered the entire region with ice thousands of metres (many more thousands of feet) thick. Today's topography is totally post-glacial. The Great Belt was eroded into existence by streams passing between the Ancylus Lake and the Kattegat. Currently it is a drowned channel.

It is possible to speak of northern and southern zones beneath the surface. The northern one consists of two v-shaped cuts more than 50 m (160 ft) deep. The southern one has a relatively shallow bottom, 30 m (100 ft) deep, showing the tops of riverine and lacustrine sediments. This configuration gives evidence that for most of its life the Great Belt hosted an outward, downhill flow.

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