Hydraulic action, Wave Quarrying, Corrasion , Abrasion, Attrition and solution
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What is Hydraulic Action?
The compressing of Air in Cracks in Cliffs when waves crash in, pressure exerted by compressed air breaks off rock pieces
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What is Wave Quarrying?
The action of waves breaking against unconsolidated material such as sand and gravel, the waves scoop out loose material like a digger
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What is Corrasion?
The hauling of sand and pebbles at a cliff face by the action of waves, chipping away at the cliff face
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What is Abrasion?
The sandpapering effect as sediment is dragged up and down or across the shoreline, this erodes and smooths rocky surfaces
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What is Attrition?
The smashing of rock pieces against eachother breaking into smaller pieces
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What is Solution (corrosion)?
Weak acids in seawater dissolve alkaline rock or the alkaline cement bonding rock particles together
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What are the 6 main factors affecting coastal erosion?
Waves, Rock type (lithology), Geological structure, Presence or absence of a beach, Sub-aerial processes and coastal management
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How do Waves affect coastal erosion?
Rate of erosion influenced by size and type of wave
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When does most erosion due to waves occur?
During winter storms, when destructive waves are at their largest and most powerful
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How does Rock type (lithology) affect coastal erosion?
The physical strength and chemistry determines rate of erosion, Tough and resistant rocks e.g. granite erode at very slow rates compared to clay and shales
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How does Geological structure affect coastal erosion?
Cracks, Joints, Bedding Planes and Faults create weaknesses in a cliff that can be exploited
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How does the Presence or Absence of a Beach affect coastal erosion?
Beaches Absorb Wave energy and reduce the impact of waves on a cliff, absence of a beach due to excessive erosion or management techniques elsewhere on the coast leave a cliff more vulnerable to waves
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How do Sub-aerial processes affect coastal erosion?
Weathering and massmovement weakens cliffs and creates scree that's easily eroded by the sea,
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How does Coastal Management affect coastal Erosion?
Presence of Structures such as groynes and sea walls will have an impact on sediment transfer (and build up of beach) and patterns of wave energy along a coastline. Trapping sediment along a coastline may deprive beaches further down= faster erosion
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What is Longshore (Littoral) drift?
Carrying of material up a beach at an angle, backwash pulls down material at right angles to the shore, due to force of gravity- process in zig-zag movement
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What are the Impacts of interrupting Longshore (littoral) drift?
Distortion of natural patterns, depriving beaches of material and exacerbating erosion. This affects stores, Flows and Sinks
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When does Coastal Deposition occur?
when the velocity of water or wind falls below a critical value for a particular size of particle and can no longer be transported
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Name 5 examples of Sediment stores/sinks?
Beaches, Spits, Mudflats, Sand dunes and offshore bars
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Other cards in this set
Card 2
Front
What is Hydraulic Action?
Back
The compressing of Air in Cracks in Cliffs when waves crash in, pressure exerted by compressed air breaks off rock pieces
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