North Sea

The North Sea is a marginal sea of the Atlantic Ocean, located between the coasts of Norway and Denmark to the east, those of the British Isles to the west, and those of Germany, the Netherlands, Belgium and France to the south. The Skagerrak constitutes a kind of bay to the east of the sea, which connects it with the Baltic through the Kattegat; it is also connected to the Baltic via the Kiel Canal. The English Channel connects it to the rest of the Atlantic to the south, while to the north it connects through the Norwegian Sea, which is the name given to the sea north of the Shetland Islands.

The tides are quite irregular since a current coming from the north and another from the south converge in it. There is much rain and fog throughout the year, and from the northwest come violent storms that make navigation dangerous.

It has an area of about 750,000 km², a length of about 960 km, and a maximum width of 480 km. It is a very shallow sea, with an average depth of 95 meters: the fact that mammoth remains have been found on the Dogger Bank, in the middle of the sea and at a depth of about 25 meters, proves that during the last ice age it was either covered with ice or was surfaced. With the thaw, the bank became a kind of last redoubt in the form of an island.

During ancient times this sea was known as Oceanum or Mare Germanicum. The current name is believed to have arisen from the point of view of the Frisian Islands, from where it was completely to the north, and by opposition to the South Sea (the Wadden Sea and the Zuiderzee, in the Netherlands). In the long run, the current name ended up being imposed, so that it was already predominant during the Modern Age. In the aforementioned Modern Age it was common to call the North Sea or the North Sea the entire Atlantic Ocean, while the entire Pacific Ocean was called the "South Sea" or "South Sea".

According to the official languages of the surrounding states, it is called Mer du Nord, in French; Noordzee, in Dutch; Nordsee, in German; Nordsjön, in Swedish; Nordsøen, in Danish; Nordsjøen, in Norwegian; and North Sea in English. In Frisian it is Noardsee and in Scottish Gaelic A' Flee in Tuath.

It has important oil and natural gas deposits, which began to be exploited in the 1970s.

Delimitation of the IHO

The highest international authority on sea delimitation, the International Hydrographic Organization (IHO), considers the North Sea a sea. In his world reference publication, "Limits of oceans and seas" (Limits of oceans and seas, 3rd edition of 1953), he assigns it the identification number 4 and defines it as follows:

In the southwest. A line linking the Walde lighthouse (France, 155'E) and the Leathercoat point (England, 51°10'N).
Northwest. From Dunnet Head (3°22'W) to Tor Ness (58°47'N) on the island of Hoy, and from there through this island to the Kame de Hoy (58°55'N) in Breck Ness, in Mainland (58°58'N), through this island to Costa Head (3°14'W) and to Inga Ness (59'17'N) in Westray,
North. From the North Point (Fethaland Point) of the Shetland Islands, through Graveland Ness (60°39'N) on the island of Yell, through Yell to Gloup Ness (1°04'W) and through Spoo Ness (60°45'N) on Unst Island, through Unst to Herma Ness (60°51'N), North and east following that parallel to the coast of Norway, being the group of the Viking Bank included in the North Sea.
East. The western boundary of the Skagerrak [A line that links Hanstholm (57°07'N 83°6'E) and the Naze (Lindesnes, 58°N 7°E)].

Limits of oceans and seap. 10.

Name

During ancient times this sea was known as Oceanum or Mare Germanicum. The current name is believed to have arisen from the point of view of the Frisian Islands, from where it was completely to the north, and by opposition to the South Sea (now the Wadden Sea, in the Netherlands). In the long run, the current name ended up being imposed, so that it was already predominant during the Modern Age.

According to the official languages of the surrounding states, it is called Mer du Nord in French, Noordzee in Dutch, Nordsee in German, Nordsøen in Danish, Nordsjøen in Norwegian and North Sea in English. In West Frisian it is Noardsee, in North Frisian Weestsiie (the Western Sea) and in Scottish Gaelic A' Flee to Tuath.

One of the first names recorded is that of "Septentrionalis Oceanus", or "Northern Ocean," which was cited by Pliny. Even so, the Celts who lived along its coast referred to it as the "Morimaru", or the "dead sea", which was also adopted by the Germanic peoples, resulting in "Morimarusa". This name refers to the "dead water" or fringes resulting from a layer of fresh water that replaced the upper part of a layer of salt water, resulting in very calm-looking water. Reference to this same phenomenon continued into the Middle Ages, for example, Old High German “giliberōt” or Middle Dutch “lebermer” or “libersee”.

Other common names in use over long periods were the Latin terms Mare Frisicum and Mare Germanicum (or Oceanus Germanicus), as well as their equivalents in other languages.

Geography

A 1490 recreation of a map of the Geography Ptolemy with the name "Oceanus Germanicus"

The North Sea is bounded on the west by the Orkney Islands and the east coast of England and Scotland, on the east by the south-western tip of the Scandinavian peninsula and west Jutland (Norwegian and Danish coasts, respectively) and to the south along the west coast of Germany, the coast of the Netherlands and Belgium, and from the extreme north of France to the English Channel. To the southwest, beyond the Strait of Dover or Calais, the North Sea becomes the English Channel, connecting to the Atlantic Ocean. To the east, it connects to the Baltic Sea through the Skagerrak and Kattegat, two straits that separate Denmark from Norway and Sweden, respectively. It is bordered to the north by the Shetlands and connects with the Norwegian Sea, which lies at the northeastern end of the Atlantic.

It stretches for 970 kilometers and has a width of 580 kilometers, occupies an area of 750,000 square kilometers and a volume of 94,000 cubic kilometers. All around the North Sea coastline are large islands and archipelagos, such as the Shetland Islands, Orkney Islands and the Wadden Islands. The North Sea receives fresh water from a number of European continental basins, as well as from the British Isles river basins. The water from the Baltic Sea also ends up, where a large number of rivers also flow, which is why it is a sea with little salinity. The main rivers that drain into the North Sea are the Elbe, the Rhine and the Meuse. The Elbe basin drains an area of 149,000 square kilometres, which includes 18 cities and their tributaries. The Rhine-Meuse delta receives water discharges from an area of 199,000 square kilometers, where 68 cities are located. About 184 million people live in the basin of the rivers that flow into the North Sea. This area contains dense industrial concentrations.

Depth

Northward from north latitude 53°24', generally speaking, the bottom of the North Sea falls inappropriately. To the south, it slopes towards the Pas de Calais.

For the most part, the North Sea lies on the European continental shelf, with a median depth of 90 meters; it has few areas deeper than 100 meters. The only exception is the Norway Trench, which runs parallel to the Norwegian coast from Oslo to an area north of Bergen. It is between 20 and 30 kilometers wide, with a depth of about 300 meters off Bergen, and a maximum depth of 725 meters at Skagerrak. In eastern Great Britain, the Dogger Bank, a plateau that originates from a large glacial period moraine, product of the accumulation of unconsolidated glacial debris, rises between 15 and 30 meters below the sea surface. This feature has produced a very rich area for fishing.

Long Forties and Broad Fourteens are areas named for depth measured in fathoms; forty fathoms and fourteen fathoms or 73 and 26 meters deep, respectively. These large shoals and others like them make the North Sea particularly dangerous areas to navigate, which has been alleviated by the application of new satellite navigation systems.

There are also great depths in the western part of the North Sea, such as Devil's Hole off Edinburgh, up to 460 metres, and some off The Wash Bay. These corridors could have been formed by rivers during the last ice age. In fact, at this point in the ice age, the North Sea level was lower than today's level (marine regression). The rivers then would have eroded certain parts then in the open that the sea currently covers (marine transgression). Most likely they are remnants of the tunnel valley, staying open for tidal currents.

Hydrology

Temperature and salinity

The median temperature in summer is 17 °C and 6 °C in winter. Climate change has been attributed to an increase in the average temperature of the North Sea. Air temperatures in January average They move in the range of 0 to 4 °C and in July, between 13 and 18 °C. During the winter months storms and storms are frequent.

Mean salinity is between 34 and 35 grams of salt per liter of water. Salinity has greater variability where there are freshwater inflows, such as the Rhine and Elbe estuaries, the connection to the Baltic Sea, and along the coast of Norway.

Water circulation and tides

The main pattern for the flow of water into the North Sea is a clockwise anti-gyre along sidewalks. The North Sea is an arm of the Atlantic Ocean and receives most of the ocean currents from the north-west opening and, to a lesser degree, a part that comes from the warm current of the small opening of the English Channel. These currents come off the coast of Norway. Both deep-water and surface currents move in different directions; shallow coastal waters with low salinity move outward, and deeper, denser waters with high salinity move inshore.

The North Sea lies within the continental shelf and has more different wave types than deeper ocean waters. Wave speeds are decreased and wave amplitudes are increased. To the North Sea there are two amphidromic systems and a third incomplete amphidromic system. In the North Sea, the difference in median tidal amplitude is between 0 and 8 metres.

Ocean currents enter mainly from the north, from the Norwegian coast

The Kelvin tide of the Atlantic Ocean is a semidiurnal wave that travels northward. Part of the energy of this wave propagates through the Canal de la Manguera towards the North Sea. Subsequently, the wave still travels north into the Atlantic Ocean, and once past the British Isles, the Kelvin wave travels east and south, once more entering the North Sea.

Rivers

The main rivers that flow are:

• Elba, 1165 km long, leading to Cuxhaven (Germany);
• Weser, 452 km, which leads to Bremerhaven (Germany);
• the Ems, 371 km, which leads to Emden, Germany;
• the Rhine, 1233 km, and the River Mosa, 950 km, leading to Rotterdam (Netherlands);
• the Escalda, 355 km, which leads to Flesinga (Netherlands);
• the Yser to Nieuwpoort (Belgium)
• the Thames, 346 km, leading to Southend-on-Sea (Great Britain);
• the Humber in Kingston upon Hull (England)
• the Trent, 298 km, and the 84 km Ouse River, which flows into Kingston upon Hull, Great Britain;
• the Tyne, 321 km, which flows into South Shields, Great Britain;
• 47 km Forth, leading to Stirling, Great Britain;
• the Tay, 188 km, which leads to Dundee, Great Britain;

Coasts

The east and west coasts of the North Sea are jagged, formed by glaciers during the ice age. The coasts along the southern part are covered with the remnants of glacial sediments deposited. The arrival of the Norwegian mountains to the seashore has caused the creation of deep fjords and archipelagos. South of Stavanger, the coastline flattens out and there are fewer and fewer islands. Scotland's east coast is fairly similar, although less indented, than Norway's. In the north-east of England, the cliffs are lower in elevation and made up of less resistant moraines, which has resulted in the surface being more easily eroded, so that the coasts have more rounded contours. In the Netherlands, Belgium and eastern England (East Anglia), the coastline is low and marshy. The eastern and south-eastern coast of the North Sea, in the Wadden Sea, is mainly sandy and very straight, particularly in Belgium and Denmark.

The German coast of the North Sea

Coastal management

Afsluitdijk (closure check) is an important dam from the Netherlands

The southern coastal areas were originally floodplains and marshlands. In areas especially vulnerable to storm surges, people settled behind lift dykes and in natural areas with high ground, such as ridges and geests. As early as 500 BC, people were building houses. on higher artificial hills so that the flood would not affect it. It was not until the early Middle Ages, in the 1200s, that the inhabitants began to connect the one-ring dikes into a line of dikes along the entire coast, thus turning the amphibious regions of land and sea into permanent dry land.

The modern form, which has complemented the overflow of levees and lateral diversion canals, began to appear in the 17th centuries and XVIII, built in the Netherlands. The North Sea floods of 1953 and 1962 were an impetus for subsequent raising the dikes, as well as lowering the coastline to present as little surface punishment as possible from the sea and storms. Currently, 27% of the Netherlands is below protected sea level by dikes, dunes and beach apartments.

Coastal management today consists of several levels. The sloping levee reduces the energy of the incoming swell, so the levee is not assigned the impact. Levees that lie directly on the sea are especially reinforced. Of the levees in recent years, they have been repeatedly reinforced, sometimes up to 9 meters and reduced to further reduce erosion from surges, where the dunes are long enough to protect the land behind them from the sea; the dunes are planted with beach grass to protect them from erosion by wind, water, and foot traffic.

Storm Tides

Zuid-Beveland, in the flood of 1953

Storm surges have traditionally threatened in particular the coastlines of the Netherlands, Belgium, Germany, and Denmark and low-lying areas of eastern England, particularly around The Wash and The Fens. Storm surges are caused by changes in atmospheric pressure in combination with strong winds created by wave action.

The first existing record of a storm surge flood was the Julianenflut, which occurred on February 17, 1164. Among its actions, Jadebusen began to form, a bay in the Germany coast. In the year 1228, a great storm surge was recorded, which killed more than 100,000 people. In 1362, the second Grote Manndränke struck the southern coast of the North Sea. The chronicles of the time speak of more than 100,000 deaths, and a large part of the coast was lost permanently flooded by sea waters, including the legendary lost city of Rungholt. Already in the XX, the 1953 North Sea floods devastated several coastlines in surrounding countries, killing more than 2,000 people. in 1962, 315 citizens of Hamburg died in the North Sea floods of 1962. The "flood of the century" in 1976 and the northern Frisian flood of 1981 brought the highest water levels ever measured. to date on the North Sea coasts, but due to coastal defences, such as improved levee and warning systems and other modifications after the 1962 flood, the flooding only caused property damage.

Tsunamis

Location of the Dogger Bank, where a major earthquake occurred in 1931

The Storegga slides (Storegga Slide) were a series of underwater landslides, in which a piece of the Norwegian continental shelf slid into the Norwegian Sea. The immense landslides that occurred between the years 8150 a. C. and 6000 a. C., caused a tsunami up to 20 meters high that spread through the North Sea, with a larger impact in Scotland and the Faroe Islands.

The 1580 Dover (or Calais) Strait earthquake is one of the few known earthquakes in the North Sea, and measured between 5.3 and 5.9 on the Richter scale. This event caused extensive damage to Calais, both through its tremors and two tsunamis.

The largest recorded earthquake in the UK was the 1931 Dogger Bank earthquake, which measured 6.1 on the Richter scale and caused a tsunami that inundated parts of the British coastline.

Geology

Water mass in Europe between 34 and 28 million years before our era.

Shallow epicontinental seas such as the present North Sea have long existed on the continental shelf. The rift that formed the northern part of the Atlantic Ocean during the Jurassic and Cretaceous periods, about 150 million years ago, caused a tectonic movement that created the British Isles. Since then, it has existed permanently between the hills of Scandinavia and the British Isles. This forerunner of today's North Sea has grown and shrunk with the rise and fall of sea level during different geological periods. Sometimes, it was connected with other seas, like the Paratetis Sea, now disappeared.

During the Late Cretaceous, around 85 million years ago, much of modern continental Europe except for Scandinavia was a scattering of islands. In the Oligocene, between 34 and 28 million years ago, the rise of western and central Europe had almost completely separated the North Sea and the Tethys Sea, which gradually narrowed to become the Mediterranean Sea in southern Europe., and on dry land south of Western Asia. The North Sea was separated from the English Channel by a narrow land bridge until it was inundated by at least two catastrophic floods between 450,000 and 180,000 years ago. Since the beginning of the Quaternary period around 2.6 million years ago, the eustatic sea level has fallen during each glacial period and then risen again. Each time the ice sheet reached its greatest magnitude, the North Sea dried up almost completely. The current North Sea coast was formed when, after the last ice age peak, during the last ice age 20,000 years ago, when the sea began to flood the European continental shelf. The North Sea coastline is still undergoing change from worldwide sea level variations, tectonic movements, tidal movements, erosion, the rise and fall of sea levels, pebble drift...

Marine traffic

The North Sea is very important for maritime traffic. Some of the largest ports in the world are located on its coasts or on the banks of rivers a few kilometers upriver from its mouth (this is the case, for example, of Rotterdam -the third port in the world-, Antwerp, Hamburg and London), or they are easily accessible, such as Amsterdam, which means that it has highly sought-after shipping routes. It is vital to Western European trade.

Main Coastal Ports

• Calais and Dunkerque in France;
• Ostende and Zeebrugge in Belgium;
• Flesinga, Rotterdam and Den Helder in the Netherlands;
• Emden, Wilhelmshaven, Bremerhaven and Cuxhaven in Germany;
• Esbjerg in Denmark;
• Oslo, Kristiansand, Stavanger and Bergen in Norway;
• Aberdeen, Dundee and Edinburgh in Scotland (Great Britain);
• Newcastle upon Tyne, Sunderland, Kingston upon Hull, Grimsby, Great Yarmouth, Lowestoft, Colchester, Southend-on-Sea and Dover in England (Great Britain);