Plate Tectonics:
Plates: Below are examples which you need to learn for the test.
Colliding: The Himalayas are an example of the collision of two continental plates
Separating: Mid-Atlantic Ridge
Sliding Past Each Other: San Andreas Fault
Structure Of The Earth
Plate:
Plate Boundary: Where plates meet
Crust: The thin outer layer of the earth
Mantle: Consists of both hot molten and semi-hot molten rock known as magma. It moves around in very slow currents.
Outer Core: Consists of liquid nickel and iron (molten)
Inner Core: The solid centre of the earth.
Convection Currents
The earth's core heats the magma up towards the earth's crust.
As the magma rises it begins to cool.
The cool magma becomes heavier and heavier causing it to sink back towards the earths core.
This circular motion causes a continuous movement of magma (convection currents) in the mantle.
Convection currents cause tectonic plates to move very slowly.
Earthquakes
The four parts of an earthquake are:
Focus (the point within the earth where an earthquake rupture starts)
Epicentre (point on surface directly above focus)
Shock Waves (waves that transmit energy released by earthquakes, spread out in circles from core focus))
Fault (large crack in the earths crust)
Case Study: Chile
300km from capitol Santiago
35km from the pacific ocean
8.8 on the magnitude scale
More than 500 people left dead
Damage cost was $30 billion
Central towns hit by t-sunmai waves
Febuary 10th 2010
More than 400,00 severely damaged/destroyed
Volcanos
Formation of a volcano
When two volcanos separate or collide, magma can rise from the mantle.
It fills the space in the crust -vent in an eruption
Magma cools and hardens at the surface. This is called lava
Layers of ash and lava build up around the vent
This forms a cone shaped mountain with a crater
Mass Movement
4 aspects that affect mass movement are:
Water - Water makes the regolith (material) heavier, causing it to move faster down slopes
Vegetation - Roots of tree's and plants help keep the soil together, helping to prevent mass movement
Human Interaction - Humans speed up mass movement when they makes hills/slopes more unstable ex. roads/quarry
Slope or Gradient - The steeper the gradient, the faster loose regolith can travel down it
Sea
Form of erosion -
River
Form of deposition -
Process of Erosion + Deposition
Erosion:
Hydraulic Action: Motion of water hitting the surface
Abrasion: Scraping/wearing away of rocks
Attrition: Impact of rock grains hitting of each other
Solution: Minerals are dissolved in water and carried along
Deposition:
Maps
line number to the right
key on back of map
always has to be exact