- Created by: indiabonacina
- Created on: 17-04-20 15:06
HEADLANDS AND BAYS
1. On a discordant coastline, there are different hardness of rocks.
2. The soft rock is eroded back quickly to form bays
3. The hard rock erodes slower leaving the headland to stand out
CAVE, ARCH, STACK AND STUMP
1. Waves attack rock face using hydraulic action and abrasion, a crack is formed
2. Overtime the crack is enlarged to form a cave
3. Cave is widened and deepened and pushes through the headland to form an arch
4. Undercutting and weathering lead arch to collapse leaving a stack
5. Weathering and erosion wear the stack down into a stump
WAVE CUT PLATFORM
1. The sea attacks the base of the cliff between the high and low water mark.
2. A wave-cut notch is formed by erosional processes such as abrasion and hydraulic action - this is a dent in the cliff usually at the level of high tide.
3. As the notch increases in size, the cliff becomes unstable and collapses, leading to the retreat of the cliff face.
4. The backwash carries away the eroded material, leaving a wave-cut platform.
5. The process repeats. The cliff continues to retreat.
1. A spit grows the whole way across a bay wow three words how amazing
2. A sandbank developes offshore, parallel to the shore, and is moved towards the coastline by the waves and wind until it joins the mainland
3. Behind the bar a lagoon is created, where the water has been trapped and the lagoon may gradually be infilled as a salt marsh
1. sediment is carried by longshore drift.
2. When there is a change in the shape of the coastline, deposition occurs. A long thin ridge of material is deposited. This is the spit.
3. A hooked end can form if there is a change in wind direction.
4. Waves cannot get past a spit, therefore the water behind a spit is very sheltered. Silts are deposited here to form salt marshes or mud flats.
1. A tombolo is a spit connecting an island to the mainland. An example of a tombolo is Chesil Beach, which connects the Isle of Portland to the mainland of the Dorset coast.
1. The river cuts down into the valley
2. If there are areas of hard rock which are harder to erode, the river will bend around it
3. This creates interlocking spurs of land which link together like the teeth of a zip.
WATERFALLS AND GORGES
1. River flows over bands of soft and hard rock
2. Softer rock is eroded away more quickly than hard rock creating a step
3. Hardrock is undercut by erosion. becomes unstable and falls
4. Rock is swirled in river where they erode soft rock by abrasion. This creates a plunge pool
5. More undercutting means more collapse. The waterfall retreats
6. Over time it leaves behind a steep-sided gorge
1. River cliffs are features of meanders.
2. Erosion of the outside bank takes place through abrasion; as the velocity is greater here the river is able to carry larger sediment which increases the force of abrasion
3. The combined effect of this erosion causes the outside bank to be undercut and eventually causes it to collapse thereby forming a river cliff.
FLOOD PLAINS, LEVES + POINT BARS
Floodplains and levees are formed by deposition in flood.The rivers load is composed of different sized is composed of different sized particles.
Formation of flood plain
1. When a river floods the water slows down
2. Deposits material that its transporting onto land around. The floodplain is built up
3. Deposition on slip-off slopes also build up flood plains
Formation of levees
1. During a flood eroded material is deposited over a flood plain
2. Heaviest material is deposited closest
3. This deposited material builds up creating levees along river channel edges
1. River erodes laterally left and right forming a meander
2. Hydraulic action erodes the outside riverbank where water flows the fastest
3. On the inside there is a slower flow so load is deposited due to more friction. A slip off slope is formed
4. Erosion and deposition forms a meande
1. Due to erosion on the outside of a bend and deposition on the inside, the shape of a meander will change over a period of time
2. Erosion narrows the neck of the land within the meander and as the process continues, the meanders move closer together
3. When there is a very high discharge (usually during a flood), the river cuts across the neck, taking a new, straighter and shorter route
4. Deposition will occur to cut off the original meander, leaving a horseshoe-shaped oxbow lake.
A drainage basin is the area of land around the river that is drained by the river and its tributaries.
Watershed - the area of high land forming the edge of a river basin
Source - where a river begins
Mouth - where a river meets the sea
Confluence - the point at which two rivers meet
Tributary - a small river or stream that joins a larger river
Channel - this is where the river flows
UPPER COURSE OF A RIVER
- steep gradient
- small shallow channels
- “rocky” channel
- slow velocity/ speed (due to fiction with channel sides)
- sediment is large, angular
- erosion (vertical)
- mass movement : weathering due to colder wetter conditions in higher ground