Marine and aeolian deposition Flashcards
Where is marine depostion likely to occur?
Where waves are low-energy or where rapid coastal erosion supplies an abundant supply of material.
Name two situations in which deposition would occur.
(Any 2 of the following)
When sand and shingle accumulate faster than they are removed.
As waves slow following breaking.
As water pauses at the top of the swash before backwash begins.
When water percolates into the beach material as backwash takes it back down the beach.
What is aeolian deposition?
The entrainment, transport and deposition of sediment by wind.
What happens to sediment present in a large tidal range?
Large amounts of sediment exposed at low tide provides a supply to be entrained by wind.
What sized sediment is most significant in terms of depositional features at the coast?
Sand-sized sediment.
What two ways is sand transported by wind?
Surface creep and saltation.
What is sand transportation dependent on?
Wind speed, and how dry/moist the sand is.
What is surface creep?
A process similar to traction, where wind rolls or slides sand grains along the surface.
What is saltation?
Wind strong enough to temporarily lift grains into the airflow of heights of up to one metre for distances up to 20-30 m.
What type of landforms can aeolian deposition shape?
Beaches and dunes.
What is marine deposition?
When the sea lays down material when there is a reduction in energy resulting from a decrease in velocity or volume of water.
