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Chemical weathering, Coastal Classification, Coastal Features, Coastline Erosion 1, Coastline Erosion 2, Coastline Erosion 3, Coastline Erosion 4, Coastline Erosion 5, Delta, Earthflow, Earthquake intensity, Earthquakes, Fluvial Morphometry, Fluvioglacial deposits, Glacial deposits, Glacial erosion, Glacial landforms, Groundwater Deposits, Groundwater Movement, Groundwater Topographic Features 1, Groundwater Topographic Features 2, Groundwater Work, Groundwater, Mass wasting, Water flow Mature Stage, Meanders, Water flow Old Age, Physical weathering, Rapids and waterfalls, Water flow Rejuvenation, River capture, Shoreline Process, Water flow Steady state, Talus cones, Volcanic landforms, Volcanic material, Volcano types, Volcanoes, Water flow, Wind Deposits, Wind erosion 1, Wind erosion 2, Wind effects on geomorphology, World volcanoes, Water flow, Youthful stage|
The coastline provides the geomorphologic with a unique range of different environments. On the other hand, Wind and wave forces vary markedly from place to place, both locally and on a global scale. High-energy conditions prevail on the exposed west-facing coasts of temperate latitudes, and these contrast with the quieter conditions of many tropical. shorelines. Equally, the character of the coastline itself varies considerably and this produces a wide range in the rate of morphological response to marine processes.
What is popularly termed 'the shore' includes both the foreshore, which stretches from the lowest tide limit to the mean high tide limit, and the backshore, which continues along the shore to the extreme limit of high tides and storm waves. The term beach is used in this chapter to define an accumulation of marine-deposited pebbles, sand or silt.
The marine agents of erosion and deposition, waves, tides and currents, are controlled by oceanographic and climatic factors.
Man is also a fundamental factor in coastal geomorphology, and has affected coastal processes through reclamation projects, coastal protection works, leisure activities and pollution.
The factor of sea-level change is one of the most important in coastal geomorphology. Sea-level changes occur as a result of (a) eustatic or global changes in the level of the sea, as has occurred with the successive growth and wane of ice-sheets during the Pleistocene, or (b) tectonic changes in the level of the land. These tectonic changes may be isostatic-that is. adjustment to a load, as in glacial isostasy - epeirogenic, related to broad scale tilting; or orogenic, related to folding and flexuring.
The level of the sea has been both higher and lower than now, and has left emergent (raised) and submergent (drowned) features, sometimes on the same stretch of coastline. Submerged effects include rias (drowned river valleys), fjords and submerged forests. Raised beaches and platforms and abandoned cliffines are the main emergent features.
In areas affected by isostatic recovery a complex series of raised beaches often exists, reflecting the interplay of isostatic and eustatic causes.
Sea-level change is still taking place. On the evidence of tide gauge records, world-wide sea-level has been rising for the past fifty years at an average of 1.2 mm per year. Faster rates of land/sea-level change occur in areas undergoing crustal warping. In northwest Europe, the Baltic area is still rising at rates up to 10 mm a year.
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