Restless Earth Flashcards
The four structures of the earth
Inner core
Outer core
Mantle
Crust
Three type of plate margins
Destructive margins
Constructive margins
Conservative margins
Destructive margin formation
Oceanic plate meets a continental plate
Denser plate is forced down and destroyed
Creates volcanos and ocean trenches
Constructive margin formation
Where two plates are moving away from each other
Magma rises from the mantle to fill gap and cools
Conservative margin formation
Where two plates are moving sides ways past each other
OR
Moving in the same direction but different speeds
Crust isn’t created or destroyed
Formation of a fold mountain
Where tectonic plates collide the sedimentary rocks that have built up between them are folded and forced upwards
Happen at destructive plate margins
Uses of fold mountains
Farming- lower slopes are used to grow crops and steep slopes for terraced to make growing crops easier
HEP- steep sided mountains and ohh lakes make fold mountains ideal for generating hydroelectric power
Mining- these mountains contain metal ores and zig zag roads have been put in place in the sides to get to them
Tourism- used for skiing and snowboarding etc in winter and walkers come for the scenery in summer
Fold mountain case study
The Alps
12 million people
Collision of Africa and European plate
How people have adapted to the conditions in the Alps
Steep relief- goats are farmed to live in steep mountains and well adapted
Poor soils- animals graze in most high areas as the soil isn’t good for growing crops
Limited communications- roads have been built over passes and tunnels for when roads are blocked by snow
Where are volcanos found?
Destructive plate margins where the oceanic plate goes under he continental plate as it is more dense
OR
Constructive margins where magma rises up into the gap created by plates moving a part foaming a volcano
What are the different types of volcanos ?
Composite volcanoes
Shield volcanoes
The features of a composite volcano
Steep sided
Layers of ash
Layers of lava
Vent
The features of a shield volcano
Low and flat
Runny lava
Layers of lava
How do scientists try to predict volcanic eruptions in advance?
Tiny earthquakes
Escaping gas
Changes in the shape of the volcano (bulges)
Volcanic eruption case study
Montserrat
1997
19 killed
Above a destructive plate margin where the Atlantic plate is being forced under the Caribbean plate
Primary and secondary impacts of Montserrat
Primary- large areas covered with volcanic material, pyroclastic flows ruining homes,vegetation destroyed and 19 people died
Secondary impacts- fires destined buildings, population declined, volcanic ash improved soil fertility
Immediate and long term responses of Montserrat
Immediate- people were evacuated to safe areas, shelters were built, temporary infrastructure built (roads)
Long wrk responses- a risk map to key people know where the exclusion zone is, the UK provided £41 billion, an observatory has been set up to try predict
What are supervolcanoes?
Much bigger than the standard volcano which develop at destructive plate margins or over the mantle (Yellowstone National Park)
Characteristics of a supervolcano
Flat
Cover a large area
Have a caldera
Consequences of a supervolcano
Thousands of cubic kilometres of rock and ash and laver
A thick cloud of super hated gas and ash which kills people, burns etc
A blackout from has
The ash burning fields and buildings
Where do earthquakes occur?
Destructive margins
Constructive margins
Conservative margins
How can earthquakes be measured?
The Richter scale- measures the amount of energy released by a seismometer
The Mercalli scale- measures effects of an earthquake by asking eyewitnesses
What are the primary and secondary effects of an earthquake?
Primary- deaths, injuries, damaged or destroyed buildings
Secondly- landslides, blocked roads, diseases spread from lack of clean water, aftershocks, fires, broken pipes
What is the case study for tsunamis?
Japan
2011
