Coastal Depositional Landforms

Question 1

Depositional landforms

Answer 1

Beach
Sand dunes
Spits
Bars

Question 2

Beach: an acumulation of sand/ shingle at the coast

Answer 2

WHERE? found in sheltered low energy areas like bays
WHY?
1- loose sediment is carried by the sea
2-the swash of a constructive wave carries sediment towards the coastline
3- deposition occurs as the waves slow down and energy drops as they enter a sheltered area.
(they can be extended by longshore drift)

Question 3

Spits: a long narrow finger of sand/ shingle jutting out into the sea from the land

Answer 3

WHERE? on coasts where there is a lot of longshore drift
WHY?
1-longshore drift transports sand along the coast
2-change in the shape of the coastline
3-spit grows out into the sea
4-The spit is exposed to changes in the wind and wave direction
5-Saltmarshes form in the sheltered area of the spit.

Question 4

Bars : when a spit grows all the way across a bay and joins two headlands together, trapping a freshwater lake behind it (lagoon)

Answer 4

WHERE? can be offshore (a gently sloping coast may cause more friction and waves deposit further from the coastline) or onshore (moved by rising sea levels.

Question 5

Sand Dunes: large piles of sand that form at the back of sandy beaches

Answer 5

WHY?
1-‘Embryo dunes’ form around an obstacle (rocks)
2- these develop and become stabilised by vegetation to form ‘fore dunes’ and tall ‘yellow dunes’ (marram grass helps bind the sand with its long roots)
3-In time rotting organic matter/vegetation make the sand more fertile and more plants colonise the ‘back dunes’
(wind can form depressions in the sand called ‘dune slacks’ where ponds may form.