1.2 How are coastal landforms developed? - OCR A-Level Geography- Questions and Answers

1.2 How are coastal landforms developed? - OCR
A-Level Geography- Questions and Answers

1.2 Beaches (Depositional landforms (coastal landforms)) (Sources of sediment) ✔️✔️-Cliff
erosion: typically only about 5%
-Offshore: Combed from the sea bed, often during periods of rising sea levels; again about 5%
-Rivers: The remaining 90% carried into the coastal system as suspended and bed load through
river mouths



Bed load ((Beaches (Depositional landforms (coastal landforms)) (Processes))) (Diagram) ✔️✔️



Bed load ((Beaches (Depositional landforms (coastal landforms)) (Processes))) ✔️✔️Sand,
pebbles, and boulders that are moved along the bed of a stream and that are too heavy to be
carried in suspension.



Spits (Depositional landforms (coastal landforms)) ✔️✔️Spits are created by deposition. A spit is
an extended stretch of beach material that projects out to sea and is joined to the mainland at
one end.
Spits are formed where the prevailing wind blows at an angle to the coastline, resulting in
longshore drift. An example of a spit is Spurn Head, found along the Holderness coast in
Humberside.



Spits (Depositional landforms (coastal landforms)) (Diagram) ✔️✔️



Spits (Depositional landforms (coastal landforms)) (Processes) ✔️✔️1. Longshore drift moves
material along the coastline.
2. A spit forms when the material is deposited.
3. Over time, the spit grows and develops a hook if wind direction changes further out.
4. Waves cannot get past a spit, which creates a sheltered area where silt is deposited and mud
flats or salt marshesform.

,Long shore drift ✔️✔️Longshore (littoral) drift is the movement of material along the shore by
wave action. It happens when waves approach the beach at an angle. The swash (waves moving
up the beach) carries material up and along the beach. The backwash (waves moving back
down the beach) carries material back down the beach at right angles. This is the result of
gravity. This process slowly moves material along the beach and provides a link between
erosionand deposition.


The material is transported through suspension, traction, solution and saltation. Longshore drift
provides a link between erosion, transportation and deposition.


Longshore drift contributes towards the formation of a range of depositional landforms such as
spits and onshore bars. Spurn Point is a coastal spit formed by the transportation of coastal
sediment by longshore drift along the Holderness Coast. This material is then deposited at the
mouth of the Humber Estuary.



Long shore drift (Processes) ✔️✔️Long shore drift occurs as a result of wave action.
1. It happens when waves approach the beach at an angle.
2. The swash carries material up and along the beach.
3. The backwash carries material back down the beach at right angles. This is the result of
gravity.
4. This process slowly moves material along the beach and provides a link between erosion and
deposition.



Long shore drift (Diagram) ✔️✔️



Onshore bars (Depositional landforms (coastal landforms)) ✔️✔️A bar is created when there is a
gap in the coastland with water in it. This could be a bay or a natural hollow in the coastland.
The process of longshore drift occurs and this carries material across the front of the bay.

, Material is pushed up onto beaches at an 45º angle when the swash brings it onto the
coastline. The backwash takes it back out towards the sea at a right angle to the coast. Through
this process material is constantly moved along the coastline.


The deposited material eventually joins up with the other side of the bay and a strip of
deposited material blocks off the water in the bay. The area behind the newly formed bar is
known as a lagoon.



Onshore bars (Depositional landforms (coastal landforms)) (Diagram) ✔️✔️



Onshore bars (Depositional landforms (coastal landforms)) (Processes) ✔️✔️1. Following the
formation of a bay, there is a gap in the coastland with water in it.
2. The process of longshore drift occurs and this carries material across the front of the bay.
3. Swash brings material onto beaches at a 45º angle.
4. This material is moved along the coast by way of backwash (at a right angle to the coast).
5. Deposited material eventually joins up with the other side of the bay.
6. This strip of deposited material blocks off the water in the bay


The area behind the onshore bar is known as a lagoon.



Tombolos (Depositional landforms (coastal landforms)) ✔️✔️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.
Chesil Beach stretches for 18 miles. Lagoons have formed behind the stretch of beach material.



Tombolos (Depositional landforms (coastal landforms)) (Diagram) ✔️✔️



Tombolos (Depositional landforms (coastal landforms)) (Processes) ✔️✔️1. Longshore currents
and longshore drift moves sediment until a change in the shape of the coastline causes a build
up of shingle and other sediment / material.