Sand Dunes Flashcards
What is sand dune?
A sand dune is a hill of loose land.
What is needed for a formation of sand dune?
A flat beach, a large supply of sand, an object for the dune to form against, a large tidal range for drying the sand up
Explain the 3 ways sand can be transported.
creep, saltation and suspension
What is another name for traction?
Creep
Explain Creep (in sand dunes)
Sand grains or material being rolled along
Explain saltation (in sand dunes)
Sand grains or material being bounced along
Explain suspension (in sand dunes)
Sand grains or material carried along with the air
Where do sand dunes form?
They form on the back shore of an sandy beach
What is marram grass?
Type of grass which is often found on sand dunes. The grass is dense and spiky and found in tufts.
How is marram grass useful for sand dunes?
It stabilises the sand dunes and also leaves behind more nutrients for more vegetation when it dies.
What is a crest in a sand dune?
Top of a sand dune
What is a dune slack?
A trough or low point within dunes. They sometimes have water in them and they are breeding sites for certain animals
What is a water table in sand dunes?
The water under exposed ground in dune slacks.
List the name of dunes from smallest to biggest.
Embryo dune–> Fore dune –>Yellow dune—>grey dune—>mature dune
Describe the formation of a sand dune
. Wind blows and particles get accumalted due to an object.
. Heaviest grain settle in the windward side (against) the object to form a ridge
. Lighter objects may be transported and will settle on the other side of the object on the sheltered leeward side
. Repeated cycle of wind blowing up the windward side and slipping down the leeward causes the sand dune to migrate inland over a period of time
. A sand dune can itself become an obstacle meaning more sand dunes can form in front of it.
. Stronger wind causes higher dune
