The North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia, Germany, the Netherlands, Belgium, and France. An epeiric (or "shelf") sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than long and wide, with an area of around .
The North Sea has long been the site of important European shipping lanes as well as a major fishery. The sea is a popular destination for recreation and tourism in bordering countries and more recently has developed into a rich source of energy resources including fossil fuels, wind, and early efforts in wave power.
Historically, the North Sea has featured prominently in geopolitical and military affairs, particularly in Northern Europe but also globally through the power northern Europeans projected worldwide during much of the Middle Ages and into the modern era. The North Sea was the centre of the Vikings' rise. Subsequently, the Hanseatic League, the Netherlands, and the British each sought to dominate the North Sea and thus the access to the markets and resources of the world. As Germany's only outlet to the ocean, the North Sea continued to be strategically important through both World Wars.
The coast of the North Sea presents a diversity of geological and geographical features. In the north, deep fjords and sheer cliffs mark the Norwegian and Scottish coastlines, whereas in the south it consists primarily of sandy beaches and wide mudflats. Due to the dense population, heavy industrialization, and intense use of the sea and area surrounding it, there have been a number of environmental issues affecting the sea's ecosystems. Environmental concerns — commonly including overfishing, industrial and agricultural runoff, dredging, and dumping among others — have led to a number of efforts to prevent degradation of the sea while still making use of its economic potential.
(詳細はOrkney Islands and east coast of Great Britain to the west〔
〕 and the northern and central European mainland to the east and south, including Norway, Denmark, Germany, the Netherlands, Belgium, and France.〔
〕 In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean.〔〔 In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat,〔 narrow straits that separate Denmark from Norway and Sweden respectively.〔 In the north it is bordered by the Shetland Islands, and connects with the Norwegian Sea, which lies in the very north-eastern part of the Atlantic.〔〔
The North Sea is more than long and wide, with an area of and a volume of . Around the edges of the North Sea are sizeable islands and archipelagos, including Shetland, Orkney, and the Frisian Islands.〔 The North Sea receives freshwater from a number of European continental watersheds, as well as the British Isles. A large part of the European drainage basin empties into the North Sea including water from the Baltic Sea. The largest and most important rivers flowing into the North Sea are the Elbe and the Rhine – Meuse watershed.〔
〕 Around 185 million people live in the catchment area of the rivers discharging into the North Sea encompassing some highly industrialized areas.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』