Coasts – The Essentials!
Below you will find the essential elements for this topic. Make sure you revise the information on this
double sided sheet in preparation for your examination!(Remember, you may get a question on
coasts or rivers or a combination of both so it is important to revise both topics).
Weathering - the breakdown of rock in situ – this means the rock that is broken down stays within
the same area. This is different from Erosion – rocks that are eroded are broken down and removed
by rivers or the sea.
Three main types:


Physical weathering – (i) Freeze Thaw where water gets in cracks, freezes and expands and
rock in the cliff cracks; (ii) Onion Skin – differences in temperature between night and day
leads to cliff surface expanding and contracting, cracking).
Chemical – chemicals in water react with rocks and wear rocks away.
Biological – animals, plants and humans help wear down river banks.
Erosion – the breakdown of rocks which are then transported away by the sea. Four main types
apply to the sea:



Hydraulic action - the force of the waves against the foot of the cliffs can cause air to be
trapped in cracks and crevices. The pressure weakens the cliffs and parts of the cliff face
drop off.
Abrasion - rocks carried along by the sea are hurled at the base of the cliff, particularly
during storms, and chip away at the cliff(scrapping!).
Attrition - rocks being carried by the waves smash together and break into smaller,
smoother and rounder particles; forming rounded pebbles.
Solution - soluble particles are dissolved into the river (Limestone and chalk cliffs are
particularly susceptible to this).
You will need to know how the above processes help to form COASTAL LANDFORMS. The questions
can ask for written or diagram responses. You will need to know how to draw and annotate a SPIT
(one diagram),CAVES, ARCHES, STACKS and STUMPS (all four in one diagram)
You may need to know what some of the above features look like on an OS map:-
Stack
Spit