Coastal Processes and Landforms free essay sample

Swell or surging waves created by distant storms (low frequency (6-8/minute); long wavelength (up to 100m); low flatter waves (lt;1m); low energy and stronger swash than backwash Destructive Waves   Storm or plunging waves created by local winds / storms (high frequency (10-12/minute); short wavelength (lt;20m); high steep wave (gt;1m); high energy and backwash stronger than swash Fetch   the distance over which wind has blown (i. . distance a wave travels from when it starts formation to when it breaks) Standing wave clapotis   where this is deep water at a coastline with steep hard rock cliffs and so waves dont break, energy is just reflected Swash   the movement of water up a beach Backwash   the movement of water back down a beach Wave Crest   Highest point of the wave Wave Trough   Lowest point of the wave Wave Height   The distance between the crest and the trough of a wave Wave Length   The distance between two wave crests Wave Frequency   The number of waves per minute Wave Period   The time between two successive crests / troughs (secs) Wave Steepness   Ratio of Wave Height:Wave Length Wave Base   Depth below which there is no orbital movement Wave Refraction   where waves become increasingly parallel to the coast occurs as waves approach an irregular coastline Hydraulic Action   An erosion process where air becomes trapped and compressed in a joint / crack in a rock by a breaking wave, gradually breaking rock apart. We will write a custom essay sample on Coastal Processes and Landforms or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Abrasion   An erosion process where cliffs are worn away by rocks and boulders thrown against them by the waves Solution   An erosion process where acids in the sea water gradually dissolve minerals in rocks. Wave Pounding   An erosion process where the shear force of the waves constantly hitting again cliffs gradually breaks them down (waves can have considerable energy up to 30 tonnes per m2) Attrition   An erosion process where rocks and boulders become smaller as they hit against each other gradually breaking each other down. Sub-aerial processes   weathering process that can also attack coastlines, weakening and gradually breaking down rock (includes processes such as freeze thaw; biological weathering etc. Longshore Drift   the movement of material along a coastline Erosion Features  (you must learn the formation of these features and named examples) Wave-cut platform   a gently sloping rocky platform as the base of a cliff, left behind as cliffs retreat (covered at high tide) Headland   a hard resistant rocky outcrop jutting out into the sea Bay   an indent in the coastline formed due to the erosion of less resistant rock Cave   a large natural hollow in a cliff face Arch   a feature cut through a headland formed where two caves have eroded back to back Stack   An isolated pillar of rock left behind as a headland as eroded backwards. Stump   a short rocky pillar left when a stack collapses (likely to be submerged at high tide) Deposition Features Beach   an accumulation of sand and shingle formed by deposition at the shore zone where land meets the sea. Spit   long and narrow accumulation of sand / shingle, projecting into the sea with one end attached to the mainland. Tombolo   A spit that has joined the mainland to an island Offshore Bar   A ridge of shingle and sand, not joined to the mainland at high tide (it may be at low tide, although not necessarily) On-shore Bar   This is where a spit has joined two headland formed across a bay in to which no major river flows Cuspate Foreland   a triangular shaped accretion of sand and shingle, believed to be formed due to the joining of two spits (originating from opposite directions). Changes in Sea-Level and Related Features Sea Level Change   rise or fall in sea-level relative to the land Isostatic Sea-level Change   local change in sea-level related to a change in height of land relative to the sea (e. g. isostatic re-adjustment as ice melts, land gradually rises as the weight of ice has been removed resulting in a relative fall in sea-level) Eustatic Sea-level Change   global change in sea-level related to changes in global volumes of water Submerged Coastline   results from a relative rise in sea-level Emerged Coastline   results from a relative fall in sea-level Estuary   tidal mouth of a river A flooded river valley (a feature of submergence) Fjord   A flooded glacial valley (a feature of submergence) Raised Beach   A beach no longer affected by coastal processes as it is now higher than the present sea-level (a feature of emergence) Abandoned Cliff   A cliff line, which may exhibit features of coastal erosion such as caves and arches but which is no longer affected by the erosion processes which originally formed these features as it is now higher than the present sea-level ( a feature of emergence)