Depositional landforms

Question 1

What are swash aligned coastlines?

Answer 1

Waves (usually constructive) break parallel to the shore, building up large beaches.

Question 2

What are some swash aligned landforms and features?

Answer 2

Bay bars, barrier beaches.

Question 3

What are drift aligned coastlines?

Answer 3

Waves break at an angle to the coast and transport sediment down the coast by longshore drift currents.

Question 4

What are some drift aligned landforms and features?

Answer 4

-Spits
-Tombolos
-Bars

Question 5

What is a spit?

Answer 5

A stretch of sediment which extends off the coastline and is connected to the land at one end.

Question 6

How is a spit formed?

Answer 6

1. Prevailing wind carries waves at an angle towards the beach (drift aligned)
2. LSD swash and backwash movement continues past the end of the shore
3. Mudflats and saltmarshes form as sediment is deposited due to flocculation and gravity
4. A change in direction of the coast enables a spit to form as it extends whether the original coastline was located
5. The wind direction may cause it to have a recurved tip
6. The spit is stopped from growing further due to river flow.

Question 7

What is the different between a simple spit and a compound spit?

Answer 7

A simple spit is only straight or recurved whereas a compound spit is made from a series of recurved edges/minor spits. Simple spits do not have these features.

Question 8

Give and example of a Simple spit. Suggest 3 facts about the spit.

Answer 8

Spurn Head Spit:
-5.5km (3 miles) long
-reaching across the mouth of the Humber
-The material reduces where the North Sea meets the Humber Estuary

Question 9

Give an example of a compound spit. Give 2 facts about the compound spit.

Answer 9

Sandy Hook spit:
-6 miles long
-1 mile wide

Question 10

What is a bar?

Answer 10

A ridge of sand or shingle which forms across the mouth of a river, the entrance to a bay or harbour, parallel to the coastline.

Question 11

What factors determine bar development?

Answer 11

friction, wave energy, prevailing wind, velocity of an incoming river.

Question 12

What are the key processes of forming a bar

Answer 12

• Longshore drift
• Deposition

Question 13

How does a bar form?

Answer 13

1. Spit grows across a bar by LSD
2. Behind the bar, a lagoon is formed and this lagoon may be gradually infilled as a salt marsh
3. Overtime, the lagoon evaporates and becomes infilled by deposition.

Question 14

What is a barrier beach?

Answer 14

An elongated bank of sand or shingle lying parallel but not attached to the coast. If it is high enough for sand dunes to develop, its known as a barrier island.

Question 15

Give an example of a bar. Give 2 key facts about the bar.

Answer 15

Slapton Ley in Devon - 1.5 miles long, linked to the headland at Strete Gate with Torcoss

Question 16

What is a tombolo?

Answer 16

A bar or beach that connects the mainland to an offshore island.

Question 17

How are tombolos formed?

Answer 17

-They form at a drift aligned coastline where longshore drift carries sediment along the coast in the direction of the prevailing wind.
-A spit extends out from the mainland when there is a change in the shape of the headland
-the spit connects to the island due to wave refraction off the coastal island which reduces wave velocity around the island.

Question 18

Give an example of a tombolo. Give two facts about the tombolo.

Answer 18

Sainte - Marie tombolo - 200 metres long, it is a prohibited nature reserve.

Question 19

What is a cuspate foreland?

Answer 19

low lying triangular shaped headlands, extending out from a shoreline, formed from deposited sediment.

Question 20

How do cuspate forelands form?

Answer 20

-longshore drift currents from opposing directions converge at the boundary of two sediment cells.
-sediment is deposited out to sea in both directions so a triangular shaped headland forms.

Question 21

Give an example of a cuspate foreland. Give two facts about the cuspate foreland.

Answer 21

Dungeness in Kent - extends for 11km in a south-easterly direction, it was originally two spits.