Many stretches of the coastline of East Anglia, England, are prone to high rates of erosion, as illustrated by this collapsed section of the cliffs at Hunstanton, Norfolk.

Coastal erosion see also (beach evolution) is the wearing away of land or the removal of beach or dune sediments by wave action, tidal currents, wave currents, or drainage. Waves, generated by storms or fast moving moter craft, cause coastal erosion, which may take the form of long-term losses of sediment and rocks, or merely in the temporary redistribution of coastal sediments; erosion in one location may result in accretion nearby. The study of erosion and sediment redistribution is called 'coastal morphodynamics'. Image File history File links Size of this preview: 400 × 600 pixelsFull resolution (768 × 1152 pixel, file size: 355 KB, MIME type: image/jpeg) Coastal erosion of sea cliffs at Hunstanton, Norfolk UK. The white layer is chalk, the red layer is a type of limestone known as Red Chalk. ... Image File history File links Size of this preview: 400 × 600 pixelsFull resolution (768 × 1152 pixel, file size: 355 KB, MIME type: image/jpeg) Coastal erosion of sea cliffs at Hunstanton, Norfolk UK. The white layer is chalk, the red layer is a type of limestone known as Red Chalk. ... Norfolk and Suffolk, the core area of East Anglia. ... Hunstanton is a large seaside town in Norfolk, England, facing The Wash. ... Norfolk (IPA: //) is a low-lying county in East Anglia in the east of southern England. ... This article or section does not adequately cite its references or sources. ... For other uses, see Beach (disambiguation). ... A diagram showing the formation of a dune with a slipface. ... This article or section cites very few or no references or sources. ... A wave is a disturbance that propagates through space or spacetime, transferring energy and momentum and sometimes angular momentum. ... This article is about tides in the Earths oceans. ... For morphological image processing operations, see Erosion (morphology). ... “Rock” redirects here. ...

On rocky coasts, coastal erosion results in dramatic rock formations in areas where the coastline contains rock layers or fracture zones with different resistances to erosion. The softer areas become eroded much faster than the harder ones, which can result in typical landforms such as tunnels, bridges, columns, and pillars.

Pacifica, California coast before major storms of 1997. The houses shown did not survive the storm season.

Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Aerial view of the Linda Mar (San Pedro Valley) neighborhood of Pacifica, Calfornia. ...

Effect on human establishments

On sedimentary coasts, coastal erosion typically poses more of a danger to human settlements than it does to nature itself. Dunwich, the capital of the English medieval wool trade, disappeared over the space of a few centuries due to redistribution of sediment by waves. Human interference can also increase coastal erosion: Hallsands in Devon, England, was a coastal village that was washed away overnight, an event possibly exacerbated by dredging of shingle in the bay in front of it. Dunwich (IPA: ) is a small town in the county of Suffolk in England. ... For other uses, see England (disambiguation). ... Long and short hair wool at the South Central Family Farm Research Center in Boonesville, Arizona Wool is the fiber derived from the fur of animals and people of the Caprinae family, principally sheep, but the hair of certain species of other mammals such as goats and rabbits and oxes... Hallsands is a deserted village in South Devon, England, in a precarious position between cliffs and the sea, between Beesands to the north and Start Point to the south. ... Part of the seafront of Torquay, south Devon, at high tide Devon is a large county in South West England, bordered by Cornwall to the west, and Dorset and Somerset to the east. ... For other uses, see England (disambiguation). ... This article does not cite any references or sources. ... Look up shingle in Wiktionary, the free dictionary. ...

The California coast, which has soft cliffs of sedimentary rock and is heavily populated, regularly has incidents of housing damage as cliffs erode. Damage in Pacifica is shown at right. Devil's Slide, Santa Barbara and Malibu are regularly affected. Aerial view of the Linda Mar (San Pedro Valley) neighborhood of Pacifica, Calfornia. ... Devils Slide is a notorious stretch of Californias Highway 1, along San Mateo Countys coastline between Pacifica and Half Moon Bay. ... Nickname: Location in Santa Barbara County and the state of California Coordinates: , County Government  - Mayor Marty Blum Area  - City 111. ... Location of Malibu in Los Angeles County, California Coordinates: , Country State County Los Angeles Incorporated (city) 1991-03-28 [2] Government  - Mayor Ken Kearsley [1] Area  - City  100. ...

The Holderness coastline on the east coast of England, just north of the Humber Estuary, is the fastest eroding coastline in Europe due to its soft clay cliffs and powerful waves. Groynes and other artificial measure to keep it under control has only sped up the process further down the coast, because longshore drift starves the beaches of sand, leaving them more exposed. Holderness is an area of England on the coast of Yorkshire. ... Humber is also the name of one of the ranges of cars manufactured by the Rootes Group Humber is also the name of a river in Newfoundland, Canada, as well as a river and a college, both in Toronto, Ontario, Canada. ... A groyne on the East coast of England A groyne (groin in the United States) is a method of coastal defense against erosion. ...

Wave Action - basic

The four main types of wave action can be remembered in this simple way; (by the use of the word "HACC")

• Hydraulic action - this is when air in cracks on the cliff face becomes compressed by the power of the waves striking the cliff face. As this happens the air inside the crack is compressed, putting a lot of pressure on the surrounding rock. The air then expands explosively, forcing out pieces of rock. Over time, the cliff face crack breaks causing a larger crack or cave to form. The rock from the cliff face which was removed falls to the bottom of the sea bed and is used for another two wave action (Attrition and Corrasion (Abrasion)).

• Attrition - this is the when the sea grinds the rocks, and also the rock on the cliff, together, casuing it to become smoother reduced in size. As the sea rocks from side to side it moves the scree causing pieces of scree to collide with other pieces of scree thus causing them to become reduced in side and smoothed and rounded. As well as colliding with other pieces of scree the scree also collides with the cliff face base causing pieces of rock to be broken of the base of the cliff face contributing to this wave action and one more (Corrasion (Abrasion)).

• Corrasion (Abrasion) - this is when the waves break on the cliff face pounding the cliff face slowly eroding it. Along with the cliff face being eroded by the power of the sea the sea also uses the scree from other wave actions. As the sea pounds the cliff faces it also uses the scree to batter and break off pieces of rock from higher up the cliff face which can be used for this same wave action or one other (Attrition).

• Corrosion - this is when the sea uses its low pH (any thing below pH 7.0) to corrode away the rocks on the cliff face. Usually the only cliff faces to be greatly eroded in this manner would be limestone cliff faces as they have a high pH and would be easly eroded by a low pH. The rocking action of the sea also makes it easier for the sea to erode limestone cliff faces as the rocking action of the sea acts as the sturing motion in a chemistry experiment which helps to speed up a corrosive experiment.

Wave action - extra detail

The ability of waves to cause erosion of the cliff face depends on number of factors, which include: A WAVES Photographer 3rd Class The WAVES were a World War II era division of the U.S. Navy that consisted entirely of women. ... For morphological image processing operations, see Erosion (morphology). ... “Precipice” redirects here. ...

• The hardness or ‘erodibility’ of the rocks exposed at the base of the cliff
  • The key factors in determining erodibility include the rock strength along with the presence of fissures, fractures, and beds of non-cohesive materials such as silt and fine sand.
• The rate at which cliff fall debris is removed from the foreshore
  • Debris removal from the foreshore is dependent on the power of the waves crossing the beach, and this energy must reach a critical level or material will not be removed from the debris lobe. On many cliffs these debris lobes can be very persistent and may take many years before they are completely removed.
• The presence or absence of a beach at the base of the cliff
  • Beaches help dissipate wave energy on the foreshore and can provide a measure of protection to the cliff from marine erosion.
• The stability of the foreshore, or its resistance to lowering
  • Lowering of the beach or shore platform through wave action is a key factor controlling the rate of cliff recession. If the beach is not lowered the foreshore should widen and become more effective at dissipating the wave energy, so that fewer and less powerful waves reach the cliff.
• The adjacent bathymetry
  • The nearshore bathymetry controls the wave energy arriving at the coast, and can have an important influence on the rate of cliff erosion.
• The supply of beach material in the coastal cell from updrift
  • The provision of material eroded updrift coming onto the foreshore beneath the cliff will help ensure a stable beach, thus providing a measure of protection.

Look up hardness in Wiktionary, the free dictionary. ... “Rock” redirects here. ... Fissure is a groove, natural division, deep furrow, or cleft found in the brain, spinal cord, and liver; or an unnatural tract found most commonly in the anus. ... Wikipedia does not yet have an article with this exact name. ... Silt is soil or rock derived granular material of a specific grain size. ... For other uses, see Sand (disambiguation). ... Debris (French, pronounced (IPA) dibri) is a word used to describe the remains of something that has been otherwise destroyed. ... The foreshore, also called the intertidal or littoral zone, is that part of a beach that lies between average high tide and average low tide. ... For other uses, see Beach (disambiguation). ... Shore A shore or shoreline is the land at the edge of a large body of water, such as an ocean, sea, or lake. ... In macroeconomics, the definition of recession is a decline in any countrys Gross Domestic Product (GDP), or negative real economic growth, for two or more successive quarters of a year. ... Bathymetry is the underwater equivalent to topography. ...

Factors affecting the erosion rate

First order (most important)

• Geological structure and lithology: hardness, height, fractures/faults
• Wave climate: prevailing wave direction
• Sub-aerial climate: weathering (frost, etc.), stress relief swelling/shrinkage
• Water-level change: groundwater fluctuations, tidal range
• Geomorphology

Second order

• Weathering and transport slope processes
• Slope hydrology
• Vegetation
• Cliff foot erosion
• Cliff foot sediment accumulation
• Resistance of cliff foot sediment to attrition and transport

Third order

• Coastal land use
• Resource extraction
• Coastal management

See also

• Coastal and oceanic landforms
• Natural arch
• Blowhole
• Bioerosion
• Modern recession of beaches
• Coastal defense
• Beach nourishment
• Streisand effect#Etymology
• Submersion

A landform comprises a geomorphological unit. ... Rainbow Bridge was formed by a meandering watercourse. ... The blowhole of Monks Cave, a sea cave near Aberystwyth In geology, a blowhole is a cavity formed in the ground at the inland end of a sea cave. ... Bioerosion describes the erosion of hard ocean substrates by living organisms by a number of mechanisms. ... This article is considered orphaned, since there are very few or no other articles that link to this one. ... Coastal defenses are objects and engineering techniques used to defend coasts against erosion and flooding. ... Before and after photos of beach restoration efforts, Florida coastline, USA. Beach nourishment device Beach nourishment is a complimentary term that describes a process by which sediment (usually sand) lost through longshore drift or erosion is replaced on a beach. ... The Streisand effect is a category of Internet phenomena in which an attempt to censor or remove (in particular, by the means of cease-and-desist letters) a certain piece of information (for example, a photograph, file, or even a whole website) instead backfires, causing the information in question to... Submersion (Coastal Management), is the sustainable cyclic portion of coastal erosion where coastal sediments move from the visible portion of a beach to the submerged nearshore region, and later return to the original visible portion of the beach. ...

External links

• Coastal Erosion Information from the Coastal Ocean Institute, Woods Hole Oceanographic Institution
• Wave Erosion
• Examine an example of wave erosion
• Erosion & Flooding in the Parish of Easington
• Some interesting teaching resources
• Examples of coastal landforms

Images: The Woods Hole Oceanographic Institution (WHOI) is a private, nonprofit research and higher education facility dedicated to the study of all aspects of marine science and engineering and to the education of marine researchers. ...

• Work to reduce coastal erosion at Lyme Regis in Dorset 2006
• Images of Coastal features