Slumping - CoastalAre they fast or slow?Fast

How does it happens?

• Waves attack softer clay• The clay is undercut by waves• The overlying rock is not supported by clay• Large chunks break away and slump in a rotational movement into the sea

Conditions needed for slumping

• There needs to be softer rock underlying harder rock• The waves should be able to easily attack the cliffs allowing undercutting• Often happens after a period of heavy rain which leaves permeable overlying rock saturated and heavy.

Mass Movement

LandslidesAre they slow or fast?Fast

How does it happen?

• After heavy rain water builds up and lubricatesthe plane between layers of rock. • It also adds weight which increases the effectof gravity.

Rock Falls

Are they fast or slow?Fast

How does it happen? When the temp fluctuates around zero.During the day water enters cracks in the rock. At night it freezes and expands. This pushes The rock either side out. The next day it thaws and the water enters Deeper into the crack. That night it Freezes again. Eventually the rock Will weaken and fall off. ThisCreates a pile of rocks at the bottomof the cliff. This is called a scree slope.

Soil CreepIs it fast or slow?V. slow

How does it happen?• Rain falls, soil particles expand• Soil dries out• Soil particles contract down Slope (under the force of gravity)• Every wetting and drying moves the particles down slope a tiny bit• Heating and cooling can also do this• Splashing of rain dropsExplodes fine particles down Slope• Trampling by animals/ people encourage it

SolifluctionFast or slow?Slow

How does it happen?• Very similar to soil creep but a bit faster• Common on hillsides in Scotland• Movement down slope as a result of alternate freezing and thawing of soil which has a high water content

Earth flows and Mud flowsFast or slow?Fast

How does it happen?• Heavy rain soaks into top soil• Water can not drain away easily due to subsoil being impermeable• Water fills up the air spaces• Soil lubricated and heavy, it moves down slope• Rapid movement of soil saturated by water• Common in areas of sparse veg’ on a steep slope after period of heavy rain

Landscape EvolutionLandscapes are the result of two major sets of processes at work:

Mountain building - Either from the formation of volcanoes or from mountains being formed when two plates collide and push the rocks up.

Denudation – Where mountains are worn down by erosion over 1000s of years. The denuded material is transported to the sea where it is deposited.

Denudation is a set of operations which form an interactive system called the Rock Cycle

Weathering – The weakening of the rock by exposure to the air, temperature changes and water.

Erosion – The removal of rock

Transportation – The transportation of the eroded material by rivers, glaciers, wind, sea

Deposition – Where the rocks are deposited on the sea floor or lake beds or on lowlands

Rock TypesIgneous - Volcanic rocks. Either cooling on the surface (basalt) or underground (granite)

Sedimentary - Sediment laid down in layers on the sea bed or lake beds. The bottom layers are sqeezed and heat and pressure turn them to rock.

Metamorphic - Rocks that are changed by heat and pressure