P1. Section C Flashcards
Give 9 features of constructive waves
- have little energy
- build the beach up
- have strong swash which pushes material up the beach
- lower height
- causes deposition
- created by the wind
- rushed back out to the sea under the force of gravity
- Constructive waves have a longer wavelength than destructive waves which means individual waves are spread quite far apart.
- Constructive waves have a low frequency (about 7-10 waves arrive at the beach each minute).
Give features of destructive waves
- have lots of energy
- have strong backwash because they have plenty of energy left
- Destructive waves cause most of the erosion of coastlines.
- Destructive waves have a stronger backwash than swash, meaning they drag more material away from the coastline than is deposited on the shore. it
- taller height
- created by the wind
- rushed back out to the sea under the force of gravity
- Destructive waves have a high frequency. They have around 10-15 waves per minute.
which type of waves are dominant in winter time?
destructive waves
What are the 4 main processes of erosion?
- hydraulic action
- abrasion
- attrition
- solution
what is hydraulic action?
waves crash against rock and compress the air in the cracks. This puts more pressure on the rock. Repeated compression widens the cracks and causes bits of rock to break off.
what is abrasion?
when eroded particles in the water scrape and rub against rock, removing small pieces
what is attrition?
eroded particles in the water collide, break into smaller pieces becoming more smaller, rounder and smoother
what is solution?
soluble materials (e.g limestone) dissolve in the water and are carried along
What is erosion?
the wearing away and removal of material by a moving force (e.g a wave)
What is weathering?
wearing away of rock in situ (staying still)
What are the 3 types of weathering?
- mechanical
- chemical
- biological
what is mechanical weathering?
the disintegration (breakdown) of rocks without changing its chemical composition
what is chemical weathering?
the disintegration (breakdown) of rocks by changing its chemical composition
what is biological weathering?
weathering due to the actions of flora and fauna.
Explain the process of freeze - thaw (mechanical weathering)
- water enter the cracks of rocks
- when the water freezes it expands, which puts pressure on the rock
- when the water thaws (melts) it contracts, which releases the pressure on the rock
- repeated freezing and thawing widens the cracks and causes the rock to break up
Explain the process of Carbonation (chemical weathering)
- Rainwater has CO2 dissolved in it, which makes it a weak carbonic acid .
- Carbonic acid reacts with rock that contains calcium carbonate
3, so the rocks are dissolved by rainwater
What are the 4 types of transportation?
- Traction
- Saltation
- Suspension
- Solution
what is traction?
large particles like boulders are pushed along the sea bed by the force of the water
what is saltation?
smaller pebbles bounce along the seabed by the force of the water
what is suspension?
small particles e.g clay and sand flow are carried along the water, not touching the seabed
what is solution?
soluble materials (e.g limestone) dissolve in the water and are carried along
what is a headland?
resistant rock that protrudes in to the sea
what is a bay?
less resistant rock that has eroded/ retreated back in to the coast
what is concordant coastline?
are made up of alternating bands of hard and soft rock that are parallel to the coast
what is discordant coastline?
are made up of alternating bands of hard and soft rock at right angles to the coast
n.d Explain the formation of headlands and bays.
n.d Explain how a stump is formed?
What is mass movement?
the downward movement of sliding material under the influence of gravity
- causes coasts to retreat rapidly