G1C: Physical Landscapes in the UK Flashcards
Definition
Landscape
The character of an area resulting from the action and interaction of natural and human elements
Define and give examples of the 3 common types of rocks in UK
Sedimentary- Form from the accumulation of sediments of rocks and organic matter. They settle in layers in large bodies of water and the pressure builds up and binds them together.
Igneous- Formed from cooling of lava. Cooling slowly makes granite. Cooling quickly makes basalt.
Metamorphic- Exisiting types of rocks go through high pressure and temperature within the earth. The process called metamorphism changes the mineral composition without melting it.
Definiton
Relief
A term used to describe physical features of a landscape
Includes: Height above sea level/Steepness of slopes/Shapes of landscape features
How do waves form
By wind blowing over the sea. Friction with the water causes waves to form. The distance the wind blows across the water is called the fetch. The longer the fetch, the more powerful the wave.
What are the 2 types of wave explain each
Constructive- These waves have longer crests and have a strong swash. Meaning they push and deposit more sand as they reach the beach. It grows the beach.
Destructive- These waves have shorter crests and a strong backwash. As they reach the beach they pull sand and even pebbles.
What are the 3 types of weathering
Physical- The breaking of rocks
Chemical- Caused by chemical changes for exmaple rainwater which is slightly acidic can break down rocks.
Biological- Due to animals and plants burrowing and rapid growth of plants breaks through rock.
Describe 3 examples of weathering in cliffs
Freeze thaw (mechanical)- Water collects in cracks or holes in the rock. At the night this water freezes and expands and makes cracks in the rock bigger. Ice expands and repeatedly cracks rocks.
Salt weathering (Mechanical)- When salt water enters crack then water evaporates away. Salt expands which puts pressure on rock causing it to break off.
Carbonation (chemical)- Rainwater absorbs CO2 from the air and becomes slightly acidic. Contact with alakaline rocks causes a reaction to occur.
Definiton
Mass movement
The downward movement or sliding of material under the influence of gravity.
Occurs after weathering when rocks have been losened
5 types of coastal erosion explain each
Solution-Dissoliving of soluble chemicals in rocks
Abrasion- Pebbles grinding over a rocky platform causing it to become smooth
Hydraulic action- Power of waves smashing into the rock causing them to break or explode with pressured air and water
Attrition- Rock fragments knock into each other causing them to become smaller
Corrasion- Fragments of rock are hurled at the cliff and break it down. They erode the rock.
4 different ways that sediment is transported
Solution- Dissolved chemicals
Suspension- Particles suspended within the water
Saltation- Bouncing motion of particles too heavy to be suspended
Traction- Large pebbles rolled across seabed
Explain Process
Longshore drift
Movement of sediment along the beach in a zig-zag pattern due to the swash and backwash of the waves.
How are headlands formed
A cliff face consists of soft and hard rocks. As waves crash into the cliff face. The more resistant rock does not erode as quick so protudes out forming headlands.
How are stacks formed and what is an example
Old Harry Rocks
Cracks in the cliff are made wider by salt crystillisation and freeze thaw weathering/abrasion.
Crevices become larger due to abrasion and hydraluic action. This creates a cave.
Cave become larger creating an arch. More weathering occurs.
Once the arch has collapsed this leaves behind a stack. The stack sticks out of the sea and continues getting weathered and eroded. This leads to the stack becoming thinner.
Overtime stack becomes eroded by hydraulic press or waves and they will dissapear in storms.
Beaches
Are deposits of sand
How are dunes made
Embryo dunes form around obstacles such as plants.
Develop and stabilise by vegetation to form fore dunes. Marram grass is adapted to the windy conditions.
Rotting vegetation adds organic matter to the sand making it more fertile.
Wind can form depressions in the sand called dune slacks in which ponds may form.
How are spits and bars formed
Spit- Longshore drift carries sand along the coast and it grows out to the sea. The changes in wind and wave change the spits direction. Salt marsh forms behind spit.
Bars-When a spit traps a freshwater lake behind it it creates a bar.
Hard engineering and 3 examples
Hard-Artificial structures to control natural processes.
It is expensive but very effective.
Sea walls-Curve waves energy back into itself
Groynes-Stop longshore drift
Rock armour-Absorbs waves energy.
Soft engineering and 3 examples
Soft-more environmentally-friendly methods that work with natural processes.
More appealling so can get more tourists
Beach nourishment-Adding more sand to beaches
Dune regeneration- Marram grass can be grown so that dunes can gro and stabilise.
Dune fencing- Fences are placed to encourage dune growth.
Explained managed retreat
Managed retreat is allwoign the sea to flood land depending on the inhabitants and the value of land.
Drainage basin
An area of land drained by a river and its tributaries.
What is the speed of the river as it comes down from mountains and fiferent types of erosion
Upper Valley- Very fast and vertical erosion with lots of hydraulic action.
Middle- Slower and vertical erosion and laterla erosion and more deposition
Lower-Channel at its widest and slowest more depsotion than erosion
Why do smaller rocks get deposited later in the river
As the river loses more energy down the river.
What occurs at waterfalls
The river runs over hard rock and falls onto softer rock. This cuts through the rock eroding it away through hydraulic action. The waterfall retreats due to erosion and forms a gorge.
Levee definition
Raised river banks
