10.5 Coastal deposition landforms Flashcards
What are beaches?
➢ Beaches are deposits of sand and shingle at the coast
How are sandy beaches formed?
➢ When waves entering the bay are constructive waves
How are pebbles beaches formed?
➢ These high-energy environments wash away the finer sand leave behind the larger pebbles
➢ These come from nearby eroded cliffs
What are dunes?
➢ Sands that has been deposited on the beach
How are embryo dunes formed?
➢ Embryo dunes form around deposited obstacles such as pieces of wood or rocks
How are fore dunes and tall yellow dunes formed?
➢ The embryo dunes develop and stabilize by vegetation to form the dunes
➢ The sand is bonded together by grass which are adapted to the wind by having long roots to find water
How is the sand made more fertile?
➢ Rotting vegetation in time adds organic matter to the sand making it more fertile
How are dune slacks formed?
➢ Wind can form depressions in the sand called dune slacks, in which ponds may form
What is a spit?
➢ Long narrow finger of sand or shingle jutting out into the sea from the land
Where do spits form?
➢ When there is significant longshore drift
How do spits form?
➢ Longshore drift transports sand along the coast
➢ If coastline changes orientation and bends sharply - sediment is then deposited out to sea
➢ Forms an extension from the land
How to spits become curved?
➢ Strong winds or tidal current can cause the end of the spit to become curved to form a feature called a recurved end
What are saltmarshes?
➢ An area of coastal grassland that is regularly flooded by seawater
Where do saltmarshes form?
➢ In the sheltered water behind the spit - deposits of mud have built up
Why are saltmarshes important?
➢ Important wildlife habitats and over-wintering grounds for migrating birds
