Please enable JavaScript.
Coggle requires JavaScript to display documents.
Earth's Structure - Coggle Diagram
Earth's Structure
Core Structure
Mantle - Nearer the earth's core, so is liquid, with a plastic and malleable texture. It is 3000km thick.
Outer Core - Made up of Nickel and Iron and is liquid, 2300km thick.
Crust - There are two types of crust: oceanic and continental. Continental is older and harder. It subducts beneath continental as it is denser. Upper mantle is included here as it is solid. It is 30 - 60km thick.
Inner Core - So much pressure is applied that it condenses and solidifies, mad up of nickel and iron. 1200km thick.
Convection Currents
Step 2 - The rock is heated, causing the particles to move around and spread out, reducing the density, and causing it to rise towards the crust.
Step 3 - The tectonic plates provide frictional force and causes them to slide to the side. In some areas the oceanic tectonic plates subduct, causing the rock to sink back to the bottom, but in some weak spots, it melts the plates and rises towards the surface.
-
-
Tectonic Plates
Continental Plates
Made up of old rock, 1500km thick. They are of lower density. An example is the North American Plate
Oceanic Plates
Made of younger and denser plates. The friction from the convection currents causes them to drift around over millions of years. This causes a change in continental plates' relative position.
Plate Boundaries
Collision Convergent
Two continental plates meet. Due to their low densities, neither can subduct, so they both rise and fold to form mountains. E.G The Himalayas
Destructive Convergent
Oceanic and Continental Plates meet, the oceanic plate subducts, forming a Trench. Pressure builds up in the Benioff zone, and when the oceanic plate melts as it nears the core, the pressure is released, causing an earthquake. E.G Nazca Plate subducting underneath the South American Plate.
-
Constructive Divergent
Convection currents cause a gap in between tectonic plates, through which the magma rises, cools, solidifies and forms a volcano. E.G Mid Atlantic Ridge