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33 Cards in this Set
- Front
- Back
Waves |
Wind causes friction at surface of the sea Energy from the wind causes the water to move forward in a circular motion Top = Crest Bottom = Trough |
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Fetch |
The distance the wind can travel uninterrupted |
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Swash |
Pushes material up on the beach |
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Longshore Drift |
Waves travel towards the beach at an angle, driven by the prevailing wind Backwash runs out at a 90 degree angle - following gravity's pull In this way, material is transported along the coastline |
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Longshore Drift Diagram |
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Constructive waves |
Deposition helps build beaches Strong swash, weak backwash Low waves Common in Summer |
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Destructive waves |
Erosion destroys beaches Weak swash, strong backwash High, frequent waves Common in Winter |
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Biological weathering |
Caused by living organisms Eg: trees and burrowing animals |
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Chemical weathering |
Involves a chemical change taking place Only affects certain rocks (such as limestone) Eg: Acid rain |
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Mechanical weathering |
Usually occurs due to the atmosphere, but does not involve chemical change Eg: Freeze - thaw |
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Freeze - thaw |
Day: Water collects in cracks in the rock Night: Water freezes and expands. This causes the cracks to grow Day: Rock breaks off and collects as scree at the bottom Process repeats |
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Mass movement |
The downhill movement of material under the influence of gravity Eg: Rockfall, Mudflow, Landslide, Rotational slip |
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Rockfall |
Fragments of rock break away from the cliff face Often caused by freeze - thaw |
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Landslide |
Blocks of rock slide downhill |
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Mudflow |
Saturated soil and weak rock flows down a slope Often near a river or stream Lack of vegetation |
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Rotational slip / landslip |
Slump of saturated soil and weak rock along a curved surface |
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Beaches |
Formed in sheltered environments - such as bays Swash is stronger than backwash Deposition occurs |
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Spits |
Created by Longshore Drift Deposits material May create a hook, if the direction of the wind changes Cannot connect 2 pieces of land, as a river flows past, washing away material Salt marshes are formed behind |
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Bars |
Formed like a Spit No river to break through Connects 2 pieces of land A lagoon is formed behind |
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Tombolo |
Formed like a spit No river the break through Connects an island to the main land |
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Spits - Spurn head (Holderness coast) CASE STUDY |
A spit A Site of Special Scientific Interest Home for rare birds (Merlin) and plants (Sea rocket) |
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Bars - Slapton Ley (South Devon) CASE STUDY |
Natural Nature Reserve An SSSI Home to Eels and Badgers |
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Cliff recession |
Similar to a waterfall Mainly chalk, limestone or clay cliffs 1. Waves attack the base of a cliff 2. Mention types of erosion 3. Over time the cliff will be undercut 4. A cut notch / platform will be created (an overhang) 5. It breaks off and collects as scree |
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Headlands and Bays |
Hard Rock --- Soft Rock --- Hard rock Erosion of softer rock More resistant rock left behind Headland = Harder rock Bay = Softer rock |
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Caves, Arches, Stacks and Stumps |
A fault in a Headland Waves and freeze - thaw cause erosion Erode partially through = Cave Erodes through fully = Arch Top of arch collapses = Stack Stack falls over due to erosion at base = Stump |
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Hard engineering |
>>Sea wall = Curved concrete wall. Reflects sea's power >Adv: Effective Used as a walkway >Dis: Expensive to build and maintain >>Rip Rap = Large boulders at foot of cliff. Forces wave to break, reduces erosion >Adv: Fairly cheap to maintain Create interesting coat >Dis: Expensive to transport Don't fit with local geology >>Groynes = Stop Longshore Drift. Trap sediment >Adv: Bigger beaches = more tourism Not too expensive >Dis: Unnatural and unattractive Starve other beaches of material |
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Soft engineering |
>>Beach nourishment = Adding material to build up beaches. >Adv: Usually local material Cheap, easy to maintain >Dis: Needs constant maintenance >>Dune regeneration = Grass planted to help hold sand into place >Adv: Looks natural Cheap Environmentally friendly >Dis: Takes time for grass to grow Damaged by walkers >>Marsh creation = Areas flooded. Creates salt marsh, acts as a barrier >Adv: Cheap Creates habitats >Dis: Land can't be used for anything else Landowners have to be paid for loss of land |
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Salt marshes |
Formed behind a spit |
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What causes rising sea levels |
Melting ice on land -- Not icebergs Global warming - seas warm up, causing water to swell and expand. Larger volume |
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Social factors affected by rising sea levels |
Houses destroyed - flooding Fresh water contaminated |
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Economic factors affected by rising sea levels |
Loss of tourism Airports at sea level (no imports) Disruption of fishing industry Costly sea defense |
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Environmentalfactors affected by rising sea levels |
Destroy habitats Loss of top soil - Plants / crops not able to grow Loss of beaches - higher flooding |
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Politicalfactors affected by rising sea levels |
Ask for aid to build defenses Reduction of green houses gases Buy land to evacuate residents at risk |