Flashcards in Coastal systems& landscapes Deck (18):
What is the first step to the coastal sediment budget?
More material is added to the cell than is removed. This causes a net accreation of material.
What type of budget is it when material is added to the beach?
Positive budget or a surplus of sediment.
The positive budget or surplus of sediment causes the shoreline to do what?
Build towards the sea.
When more material is removed from the cell then added what is this called?
A negative budget or a deficit to sediment supply.
The negative budget or a deficit to sediment supply does what to the shoreline?
Shoreline retreats landward.
Oxidation causes rocks to do what?
Disintergrate when the oxygen dissolved in water reacts with the rock minerals.
When the oxygen reacts what does this produce ?
What is surface creep?
Similar to traction, where the wind rolls or slides sand grains along the surface.
What is saltation?
Where the wind is strong enough to temporary lift the grains into the airflow to heights up to 1 meter.
When does deposition occur?
When sand& shingle accumulate faster than they are removed.
When deposition occurs the waves do what?
They slow following breaking
For deposition to occur the water does what?
Water pushes at the top of the awash before backwash begins.
When does marine deposition take place?
Where waves are low energy or where rapid coastal eroison provides a large amount of material.
Marnie deposition also occurs when water percolates into what ?
The beach material as backwash takes it back down the beach.
Where do Marnie processes operate?
Upon the coastline and are connected with the sea, such as waves.
Where do sub-aerial processes operate on?
On the land but effect the shape of the coastline, such as weathering, mass movement& run off.
When does hydration occur ?
Rocks are more susceptible to further chemical weathering. Involves further addition of water, rock expands.