coasts Flashcards
What is a littoral zone?
Consists of offshore, nearshore, foreshore and backshore, is a coastal plain and eventually may lead to dynamic equilibrium.
Name an input and output of littoral zone.
sediment
Describe high and low energy coastlines
destructive waves and greater erosion, constructive waves and lesser erosion.
Describe a concordant coastline.
Has bands of soft and hard rock, which are parallel to the sea.
Describe discordant coastline.
alternating bands of soft and hard rock perpendicular to sea.
What are Dalmatian coasts caused by?
concordant coasts
What are headlands and bays caused by?
discordant coasts
What is a dip and its different forms?
Dip is the angle of the rock, if towards the sea can cause mass movement if towards land can cause hydraulic action.
What are joints and faults?
Weaknesses within the rock and this leads to erosion of rocks if there are more faults and faults.
what does bedrock lithology mean?
physical properties of rock.
Explain formation of igneous rocks.
formed from magma, has crystals which make it more resistant.
Explain formation of sedimentary rocks.
layers of sediment result in rock, which is weaker.
Explain formation of metamorphic rocks.
heat changes sedimentary and igneous rocks, rock is metamorphosed, crystals develop.
What are the different plants in dunes?
Xerophytes are dry plants and halophytes grow in salty conditions.
What is corrosion?
when chemical reactions break down substances.
Describe the formation of a wave cut platform.
Sea hits a certain position creating a fault, this results in retreat and a wave cut notch, eventually the cliff overhead breaks.
Explain the formation of stacks, stumps caves etc.
Caves, arch, stack, stump.
What are spits, tombolo’s, bars and cuspate forelands?
sediment is carried by wind, sediment connects to other land, sediment connects to island, 2 spits form which join creating land.
What is a sediment cell?
source where material is found comes via rivers, transfer is where material is moved and sink is where material is deposited.
What is chemical weathering?
when chemical composition of rock changes results in rock breakdown. i.e carbon dioxide mixes with rain creating carbonic acid.
What is mechanical weathering?
rock breakdown without change in chemical composition.
What is biological weathering?
rock breakdown by biological beings
What are slides, slumps and rockfalls?
material falls in straight line, at an angle and material separates.
What is isostatic change?
when land is uplifted as ice is weighing down on land this results in sea level fall and fossil cliffs.
What is eustatic change?
When ice melts and increase sea volume resulting in sea level rise.
What is tectonic change?
when land changes i.e rises due to tectonic plate movement.
What is an emergent coastline and what does it create?
Fall in sea level coasts, results in fossil cliffs and raised beaches.
What is a submergent coastline and what does it create?
Rise in sea level, results in fjords, rias and Dalmatians
What is the problem with hard engineering?
can damage sediment cell, this can ruin entire beaches
What are subaerial processes?
In land, air processes.
What is dredging?
Removal of sediment for construction results in retreat.
What are weather systems linked to?
pressure
What are tides linked to?
Gravitational pull by the moon.
How does wind and seasons affect erosion?
Wind moves sediment and seasons depend on energy and tides.
What is occurring in Maldives?
Removal of mangroves means there is more coastal retreat as there is a lack of trees.
What is occurring in Bangladesh?
Storm surges affecting bay of bengal, people are building shelters and moving others out of the area also Bangladesh is low lying.
What are revetments?
Walls that stop erosion, are cheaper but can make it difficult for people to move around beach.
What are groynes?
fences that are situated inground and stop erosion.
What are rip raps?
Boulders placed at the front of the beach, are cheap but can cause danger to people.
What are offshore breakwaters?
line of rocks that create gentler waves however can disrupt waves.
What are sea walls?
walls of concrete that reflect waves back.
What is cliff regrading?
Restructuring cliff, so that it doesn’t collapse.
What is dune stabilisation?
using dunes to protect biological beings
What is beach nourishment?
depositing sediment from one area to another, this is very expensive.
What is ICZM?
Holistic coastal management. views all aspects i.e social, economic etc before building a defence.
What is considered in ICZM?
residents buildings
economy
natural environment.
What are advantages of this scheme?
Conserves area, makes everyone happy, reduces unwanted resources.
What is shoreline management?
- strategic realignment= physical processes work naturally
- Advance the line= building of protection
- no active intervention= no involvement on protection
- hold the existing defences= making sure that the existing defences are working and maintained.
What is a cost benefit analysis?
to see if something is worth installing.
What is the environmental impact assessment?
if something damages the environment.
