The border between the North Sea and the Skagerrak is at an imagined line betweenLindesnes in Norway, andHanstholm in Denmark. In the North, the North sea is open towards the Atlantic. The border between the two is an imagined line from Northern Scotland, toShetland, and then toÅlesund in Norway. According to theOslo-Paris Treaty of 1962 it is a bit more to the west and the north though. The treaty puts it at 5° East longitude, and 62° North latitude. That is at the parallel of theGeirangerfjord in Norway.
On average, the North Sea has a depth of only 94 meters. About 80 million people live near the North Sea, at most 150 km away from the coast. Together with the English Channel in the south, the southern North Sea is the busiest body of water in the world.
Its name comes from its relationship to the land of theFrisians (seeFrisia). They live directly to the south of theNorth Sea, and to the west of theEast Sea (Oostzee, the Baltic Sea), the formerSouth Sea (Zuiderzee, today'sIJsselmeer) and the today reclaimedMiddle Sea (Middelzee). But the spread of the name could also be from the view of the cities of theHanseatic League. Some of its main cities, likeLübeck,Bremen orHamburg had the same view.
Inclassical times this body of water was also called theOceanum Germanicum orMare Germanicum, meaning German Ocean or Sea. This name was commonly used inEnglish and other languages along with the nameNorth Sea, until the earlyeighteenth century. By the latenineteenth century,German Sea was a rare, scholarly usage even inGermany. InDanish the North Sea is also namedVesterhavet (besidesNordsøen), meaningWestern Ocean because it is west of Denmark.
Satellite picture of the north sea. The area marked in red is theDoggerbank.
Most of the North sea is on the EuropeanContinental shelf. On average, the depth is about 93 to 94 meters only. In the south it is very shallow, only 25 to 35 meters. In the north in thebathyal zone north of Shetland, this depth increases to between 100 and 200 metres. In the south, the depth is at most 50 metres. An exception to this is theNorwegian Trench. It is deepest there, with a depth of 725 metres. The most shallow part of it is a sand bank calledDogger Bank. In the southern part, there are many sand banks.
Looking at the satellite picture it is easy to see the geographic divisions of the North Sea:
a generally shallow southern North Sea
the central North Sea
the northern North Sea, with the Norwegian Trench, near the Skagerrak.
The southern north sea is composed of theSouthern Bight, before the coast of Belgium and the Netherlands and the German Bight before the coastline of Germany. The Dogger Bank is the limit between the southern and central parts. TheWaddenzee runs all the way fromDen Helder in the Netherlands toEsbjerg in Denmark.
The Dogger Bank covers an area about half the size of the Netherlands. There, the North Sea has a depth of between 13 and 20 metres only. The area is very famous for fishing. With some storms there are evenwaves breaking there.
The Norwegian Trench has an average depth of around 250 to 300 metres; at the entrance to the Skagerrak, the depth increases up to 725 meters. Along the trench is theNorwegian Current, which brings most of the waters of the North Sea into the Atlantic Ocean. Also, most of the waters of the Baltic Sea flow northwards here.
About 200 km east of the Scottish city ofDundee there are more trenches, known collectively as theDevil's hole. Generally, the water is about 90 meters deep there. The trenches very often are only a few kilometers in length. In these trenches, the depth increases to up to 230 meters.
In the Dover Strait the water is about 30 meters deep. At the end of the English Channel, this depth increases to about 100 meters.
In the lastice age the North Sea was covered by large areas of ice calledglaciers. About 20,000 years ago the ice melted and the North Sea was formed (made).
In the 1960s,geologists found large areas ofoil andnatural gas under the North Sea. Most of the oil fields are owned by theUnited Kingdom andNorway but some belong toDenmark, theNetherlands andGermany. Drilling began in the 1960s and led to a famous argument between the UK Government and Scottish Nationalists how the revenue (money) from the oil should be spent.
People have beenfishing in the North Sea for thousands of years. However, so manyfish are now caught there that new ones may not be able to grow fast enough to keep the fishery going.
