Aeolian processes Flashcards
What can be developed when wind reaches critical velocity and transports sediment particles?
Sand dunes can be formed
What are the condition required for the formation of sand dunes?
An abundant supply of sand
Shallow beach gradient
Tidal range allowing a large area of sand to dry out at low tide
Prevailing onshore winds
An area inland where windblown sand can accumulate
Formation of sand dunes step 1
Constructive waves deposit sediment on the beach
Formation of sand dunes step 2
Wind blowing onshore move sand inland by;
Creep-Sand is rolled along surface
Saltation - smaller sand particles bounce over the surface
Formation of sand dunes step 3
Where an obstacle or vegetation reduces wind velocity, the sand is deposited and quickly accumulates
Formation of sand dunes step 4
Plants such as sea couch grass and marram grass become established increasing sand accumulation and forming an “embryo dune”
Formation of sand dunes step 5
Continued deposition leads to embryo dunes forming a ridge
Formation of sand dunes step 6
New embryo dunes form in front of the ridge repeating the process
Formation of sand dunes step 7
Gradually the older dunes become covered in vegetation and are stabilised
