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Natural Hazards and tectonic Hazards

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• The mantle is made up of semi molten rock. The core heats up the mantle rock. The warm material rises to the earths surface. As it rises the material will start too cool and sink. This motion of rising and sinking rock forms convection currents in the mantle. The semi molten rock flows in a circular motion.
• Convection currents cause the over lying tectonic plates to move.

Slab Pull Theory

• Large, dense, heavy plates sink into the mantle at destructive plate margins and pull the rest of the plate with it.
• Magma starts to rise to the surface at the constructive plate margins and creates new land. This pushes the rest of the plate away from the plate boundary.
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Constructive plate margin

• Due to convection currents 2 plates move away from eachother this leaves a gap between the two plates. Magma rises up from the mantle to fill the gap, construction new crust. This tends to happen under the oceans. The new creation of land is called the sea floor spreading.
• volcanoes- There is no build up of pressure= gentle eruptions.
• earthquakes- There is no build up of pressure= gentle earthquakes.