C - Coastal Landforms and Landscapes of Deposition

Question 1

What are the 2 types of beaches?

Answer 1

• swash aligned
• drift aligned

Question 2

Describe the formation of a spit and salt marsh

Answer 2

• longshore drift causes the beach to extend out to sea
• the sheltered, saline environment behind the spit forms a salt marsh

Question 3

Can spits extend across an estuary and why/why not?

Answer 3

• the changing currents from the river and sea meeting prevents sediment from being deposited

Question 4

What is a compound spit?

Answer 4

A spit with multiple tips

Question 5

What is a double spit?

Answer 5

• when two spits from opposite sides of the bay reach towards each other
• unlikely to touch

Question 6

Describe the formation of a barrier beach and bar

Answer 6

• a beach or spit extends across a bay to join 2 headlands
• the trapped water becomes a brackish (slightly salty) water

Question 7

How do barrier islands form?

Answer 7

The barrier beach gets separated from the mainland

Question 8

What is a tombolo and how is it formed?

Answer 8

• a bar or beach that connects the mainland to an offshore island

Formation
- wave refraction off of a coastal island reduces wave energy
- sediment gets deposited
- may be covered during high tide if they are low lying

Question 9

What is a vegetation succession?

Answer 9

A plant community that changes over time

Question 10

Describe the plant succession at the coast

Answer 10

• pioneer plants (e.g marram grass) grow in bare mud and sand
• when they die, they release nutrients
• this allows other plants to begin to grow
• creates even more nutrients
• results in a plant succession

Question 11

Describe the salt marsh succession

Answer 11

• algal stage - algae begins to grow on bare mud
• pioneer stage - grass begins to grow and their roots stabilise the mud
• establishment stage -
• stabilisation -
• climax vegetation

Question 12

Describe the formation of sand dunes

Answer 12

• prevailing winds blow sediment to the back of the beach
• wind loses energy when it hits the developing sand dune, so even more sediment gets deposited on it
• this causes the sand dune to grow

Embryo dune - upper beach where sand starts to accumulate around an obstacle

Yellow dune - as the dune grows, vegetation may develop behind and on the back of the dune surfaces (this stabilises the dune and is the tallest of the dune sucession

Grey dune - sand becomes soil with the moisture and nutrients from dead plants (this enables even more varied plant growth)

Dune slack - water table rises closer to the surface, water trapped in the hollows of the sand dunes and enables the development of moisture-loving plants

Heath and woodland - sandy soils develop due to an increase in nutrient content, allows less brackish plants to thrive - trees also grow and a coastal woodland is formed

Question 13

Describe the formation of estuarine mudflats

Answer 13

• Deposition in estuaries behind a spit/bar, where it is trapped
• leads to a build up of mud
• builds up until it is above water level
• pioneer plants colonise the area, which results in it becoming even more trapped
• leads to a vegetation succession, and larger plants such as trees begin to grow in the area