Coastline of the North Sea

The German North Sea coast

The coastline of the North Sea has been evolving since the last glacier receded. The coastline varies from fjords, river estuaries to mudflats.

The eastern and western coasts of the North Sea are jagged, as they were stripped by glaciers during the ice ages. The coastlines along the southernmost part are soft, covered with the remains of deposited glacial sediment, which was left directly by the ice or has been redeposited by the sea.[1] The Norwegian mountains plunge into the sea, giving birth, north of Stavanger, to deep fjords and archipelagos. South of Stavanger, the coast softens, the islands become fewer.[1] The eastern Scottish coast is similar, though less severe than Norway. Starting from Flamborough Head in the north east of England, the cliffs become lower and are composed of less resistant moraine, which erodes more easily, so that the coasts have more rounded contours.[2][3] In the Netherlands, Belgium and in the east of England (East Anglia) the littoral is low and marshy.[1] The east coast and south-east of the North Sea (Wadden Sea) have coastlines that are mainly sandy and straight owing to longshore currents, particularly along Belgium and Denmark.[4][5][6]

Northern fjords, skerries, and cliffs

Lysefjord in Norway.

The northern North Sea coasts bear the impression of the enormous glaciers which covered them during the Ice Ages and created fjords, lakes and valleys along the coastline and landscape. Fjords arose by the action of glaciers, which dragged their way through them from the highlands, cutting and scraping deep trenches in the land. Fjords are particularly common on the coast of Norway.[6][7][8]

Firths are similar to fjords, but are generally shallower with broader bays in which small islands may be found.[9] The glaciers that formed them influenced the land over a wider area and scraped away larger areas.[10] Firths are to be found mostly on the Scottish and northern English coasts.[11] Individual islands in the firths, or islands and the coast, are often joined up by sandbars or spits made up of sand deposits known as "tombolos".[12][13]

North Sea cliff

Towards the south the firths give way to a cliff coast, which was formed by the moraines of Ice Age glaciers.[2] The horizontal impact of waves on the North Sea coast gives rise to eroded coasts.[2][3] The cliff landscape is interrupted in southern England by large estuaries with their corresponding fringing marshes, notably the Humber and the Thames.[8][14][15]

There are skerries in southern Norway formed by similar action to that which created the fjords and firths. The glaciers in these places affected the land to an even greater extent, so that large areas were scraped away. The coastal brim (Strandflaten), which is found especially in southern Norway, is a gently sloping lowland area between the sea and the mountains. It consists of plates of rock platforms, and often extends for kilometres, reaching under the sea, at a depth of only a few metres.[16]

Southern shoals and mudflats

The shallow-water coasts of the southern and eastern coast up to Denmark were formed by ice age activity, but their particular shape is determined for the most part by the sea and sediment deposits.[17]

Mudflats in Germany

The Wadden Sea stretches between Esbjerg, Denmark in the north and Den Helder, Netherlands in the west. This landscape is heavily influenced by the tides and important sections of it have been declared a National Park.[18] The whole of the coastal zone is shallow; the tides flood large areas and uncover them again, constantly depositing sediments.[19] The Southern Bight has been especially changed by land reclamation, as the Dutch have been especially active.[19] The largest project of this type was the diking and reclamation of the IJsselmeer.[20]

Tidal forces have formed the Frisian Islands. In the micro tidal area, (a tidal range of up to 1.35 meters (4.4 ft), such as on the Dutch or Danish coasts,[21] barrier beaches with dunes are formed.[19][22]:[217] In the mesotidal area (a tidal range of between 1.35 and 2.9 m (4.4 and 9.5 ft), barrier islands are formed;[22]:[309, 488] in the macrotidal area (above 2.9 meters (9.5 ft) tidal range), intertidal deposits raise the spring tide range 4 meters (13 ft).[19][22]:[30–31] A soft rock coast is formed in the meso-macro tidal areas located in the southern North Sea. These soft rock coastal bedrock plains are interspersed with soft rock (shale and sandstone) cliffs.[23]

The small, historically strategic island of Heligoland was not formed by sediment deposition; it is considerably older and is composed of early Triassic sandstone.[24]

See also

References

  1. 1 2 3 L.M.A. (1985). "Europe". In University of Chicago. Encyclopædia Britannica Macropædia. 18 (Fifteenth ed.). U.S.A.: Encyclopadia Britannica Inc. pp. 832–835. ISBN 978-0-85229-423-9.
  2. 1 2 3 "Development of the East Riding Coastline" (PDF). East Riding of Yorkshire Council. Archived from the original (PDF) on 2007-08-10. Retrieved 2007-07-24.
  3. 1 2 "Holderness Coast United Kingdom" (PDF). EUROSION Case Study. Retrieved 2007-07-24.
  4. ↑ Koster, Eduard A. (2005). "The Danish North Sea Coast". The Physical Geography of Western Europe (Digitized by Google Books online). Oxford University Press. p. 134. ISBN 978-0-19-927775-9. Retrieved 2008-12-05.
  5. ↑ Verwaest, Toon; Peter De Wolf; Jean-Louis Leten; Marc Leten (2005-11-23). "Windows in the dunes – the creation of sea inlets in the nature reserve de Westhoek in De Panne" (PDF). in Herrier J.-L., J. Mees, A. Salman, J. Seys, H. Van Nieuwenhuyse, & I. Dobbelaere (Eds.) Proceedings ‘Dunes and Estuaries 2005’ – International Conference on Nature Restoration Practices in European Coastal Habitats. Koksijde, Belgium: Flanders Marine Institute (VLIZ). pp. 433–439. Retrieved 2008-11-02.
  6. 1 2 "Overview of geography, hydrography and climate of the North Sea (Chapter II of the Quality Status Report." (PDF). Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR). 2000. Retrieved 2007-12-04.
  7. ↑ Geological Society of London (1877). "And Cirques in Norway and Greenland". The Quarterly Journal of the Geological Society of London (Digitized by Google Books online). HighWire Press: Published by The Society. pp. 173–176. Retrieved 2008-12-05.
  8. 1 2 International EMECS Center (2003). Environmental Guidebook 5: North Sea (PDF). International Center for the Environmental Management of Enclosed Coastal Seas (EMECS). Retrieved 2007-07-24.
  9. ↑ Philip George and son, ltd (1882). Philips' elementary atlas and geography, ed. by J.F. Williams (Digitized June 12, 2006 by Google Books online). p. 15. Retrieved 2008-12-05.
  10. ↑ Croll, James (1885). Climate and Time in Their Geological Relations: A Theory of Secular Changes of the Earth's Climate (Digitized 2006-05-15 by Google Books online). Original from Oxford University England: A. and C. Black. pp. 443–444. ISBN 978-0-7486-6228-9. Retrieved 2008-12-05.
  11. ↑ Cramb, Auslan; Magnus Magnusson (1998). "Marine Environment". Fragile Land: Scotland's Environment (Digitized by Google Books online). Edinburgh University Press. p. 101. ISBN 978-0-7486-6228-9. Retrieved 2008-12-05.
  12. ↑ May, V. J.; J. D. Hansom (2003). Coastal Geomorphology of Great Britain (PDF). Geological Conservation Review Series, No. 28. Peterborough: Joint Nature Conservation Committee. pp. 754 pp. Retrieved 2008-11-02.
  13. ↑ Hansom, J. D. "St Ninian's Tombolo" (PDF). volume 28: Coastal Geomorphology of Great Britain from Geological Conservation Review Chapter 8: Sand spits and tombolos. Joint Nature Conservation Committee: 5pp. Retrieved 2008-11-01.
  14. ↑ Penn, James R. (2001). Rivers of the World: A Social, Geographical, and Environmental Sourcebook (Digitized by Google Books online). ABC-CLIO. ISBN 978-1-57607-042-0. Retrieved 2008-12-05.
  15. ↑ Allen, John R. L. (1992). Saltmarshes: Morphodynamics, Conservation, and Engineering Significance (Digitized by Google Books online). Kenneth Pye. Cambridge University Press. ISBN 978-0-521-41841-6. Retrieved 2008-12-05.
  16. ↑ Seppälä, Matti (2005). "Atlantic Coasts and fjords Geoffrey D. Corner". The Physical Geography of Fennoscandia (Digitized by Google Books online). Oxford University Press. p. 210. ISBN 978-0-19-924590-1.
  17. ↑ "Bridlington to Skegness: Habitat: Earth heritage". Natural England. Retrieved 2007-07-24.
  18. ↑ German MAB National Committee, ed. (2005). "5. Socio-Economic Monitoring in the Schleswig-Holstein Wadden Sea Region Christine Gatje". Full of Life: UNESCO Biosphere Reserves: Model Regions for Sustainable Development (Digitized by Google Books online). Springer. p. 129. ISBN 978-3-540-20077-2. Retrieved 2008-12-08.
  19. 1 2 3 4 Salman, Albert; Jos Rademakers (2007). "The Coastal Guide to The Dutch Coast". EUCC - The Coastal Union. Retrieved 2008-12-04.
  20. ↑ "EarthShots: Satellite Images of Environmental Change IJsselmeer". U.S. Department of the Interior. 2007-05-01. Retrieved 2008-12-04.
  21. ↑ Hollebrandse, Florenz A. P. "Temporal development of the tidal range in the southern North Sea" (PDF). Faculty of Civil Engineering and Geosciences. Delft University of Technology, Delft, The Netherlands. Retrieved 2008-11-02.
  22. 1 2 3 Eisma, D.; Poppe Lubberts de Boer (1998). Intertidal Deposits: River Mouths, Tidal Flats, and Coastal Lagoons (Digitized by Google Books online). CRC Press. p. 131. ISBN 978-0-8493-8049-5. Retrieved 2008-12-04.
  23. ↑ "Habitat Dynamics at the Coast-Catchment Interface Synthesis Results Coastal habitat typology". European Land Ocean Interaction Studies. Retrieved 2008-12-04.
  24. ↑ Jaeck, Joachim (2008-07-21). "History "Exotics" on Heligoland". Archived from the original on March 13, 2005. Retrieved 2008-12-04.
This article is issued from Wikipedia - version of the 11/27/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.