Slumping - Coastal Are they fast or slow? Fast How does it happens? Waves attack softer clay

1. Mass Movement • Slumping - Coastal • Are 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.

2. Landslides • Are they slow or fast? • Fast • How does it happen? • After heavy rain water builds up and lubricates • the plane between layers of rock. • It also adds weight which increases the effect • of gravity.

3. 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. This Creates a pile of rocks at the bottom of the cliff. This is called a scree slope.

4. Soil Creep • Is 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 drops • Explodes fine particles down • Slope • Trampling by animals/ people encourage it

5. Solifluction • Fast 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 flows • Fast 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

6. Landscape Evolution Landscapes 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 Types Igneous - 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