Coasts Flashcards
What are the 4 types of coastal transportation and deposition?
- Traction
- Saltation
- Suspension
- Solution
Where are beaches found?
Beaches are found on coasts between the high water mark and the low water mark.
What are sandy and shingle beaches like?
Sand - flat and wide - sand particles are small and the weak backwash can move them back down the beach, creating a long and gentle slope.
Shingle - steep and narrow - shingle particles are large and the weak backwash can’t move them back down the beach. The shingle particles build up and create a steep slope.
What type of wave create beaches?
Constructive.
Name 3 hard engineering strategies for coastal erosion.
- Sea wall
- Rock armour
- Groynes
Name 3 soft engineering strategies for coastal erosion.
- Beach nourishment
- Dune regeneration
- Managed retreat
- Marsh creation
What are the two types of coastal weathering and erosion?
Mechanical and Chemical
What is Mechanical Weathering?
Mechanical Weathering is the breakdown of rock without changing its chemical composition.
Name 1 type of Mechanical Weathering and how the process works.
Freeze-thaw weathering - It happens when the temp is below 0 degrees. Water gets into the cracks in the rock and when it freezes it expands putting pressure on the rock and when it thaws it contracts releasing the pressure. Repeated freezing and thawing widens the cracks and causes the rock to break up.
What is Chemical Weathering?
Chemical Weathering is the beak-down of rock by changing its chemical composition.
Name 1 type of Chemical Weathering and how the process works.
Carbonation Weathering - Rainwater had C02 dissolved in it, which makes it a weak carbonic acid. The acid then reacts with the rock that contains calcium carbonate, eg. limestone, so the rocks are dissolved by the rainwater.
Name the 4 processes of waves eroding cliffs and what they do.
Hydraulic power - waves crash against the rock and compress the air in the cracks.
Abrasion - eroded particles in the water scrape and rub against the rock, removing small pieces.
Attrition - eroded particles in water smash into each other and break into smaller fragments.
Solution - weak carbonic acid in the sea water dissolves rock like chalk and limestone,
Name one coastal erosion case study.
Holderness or Christchurch Bay
Name one coastal flooding case study.
Maldives
Describe 6 impacts of coastal flooding in the Maldives
Economic - Loss of tourism, Disrupted fishing industry
Social - Houses could be damaged or destroyed, less freshwater available( fresh water will be polluted by seawater if thee levels rise high enough).
Environmental - Loss of beaches therefore destroying vital habitats and killing animals, loss of soil meaning most plants wouldn’t be able to grow.
Political -Maldivian government had to ask for $60 from Japan to build a sea wall, changes in long-term plans 9 the government may have to think about buying new land).
Give the two reasons for the sea levels rising.
Melting ice: the melting of ice on lane, e.g the antarctic ice sheet cause water that is stored as ice to return to the oceans and causes sea levels to rise.
Heating Oceans: Increases global temperature causes the oceans to get warmer and expand (thermal expansion). this increases the volume of water, causing sea levels to rise,
Give a brief overview of Holderness
The coastline is 61km long. erosion is causing the cliffs to collapse along the coastline. it has a retreating coastline, About 1.8m of land is lost to the sea every year.
Give the main reasons for the rapid erosion of Holderness
1) Easily eroded rock type- Made of clay so they are likely to slump
2) Naturally narrow beaches- beaches take up most of the impact of thee waves but if there are narrow beaches a lot more of the impact is given off to the cliffs.
3) People - Coastal defences called groynes have been built to stop material being moved further down the beach from Mappleton. Beaches become a lot narrower further down the coasts.
4) Powerful waves- Holderness faces the prevailing wind direction, which brings waves from the north east, all thee way from the arctic ocean. waves increase in power over distance so the waves are very powerful once they reach Holderness.
