Natural Hazards
- Created by: Morsey02
- Created on: 02-11-18 16:36
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- Natural Hazards
- A natural event that threatens people or has the potential to cause damage, destruction and death.
- People live near natural hazards - better nutrients for crops, cant move, trade routes.
- Plate Tectonics. The African plate moves away from the south American plate. The pacific plate is moving away from the nazca plate
- Convection currents hep transfer heat from the earths core - where magma is created.
- Conservative plate boundary - Plates go past each other but in opposite directions, friction is overcome and the plates slip causing an Equake
- Subduction - the oceanic plate is denser than the continental so it is forced under the continental when they move. Cause Equakes due to the magma rising
- Constructive - 2 plates moving apart in opposite directions causing cracks overtime they create undersea mountains.
- Collisional - 2 similar plates are forced together, they crumble and fold upwards creating mountains.
- Layers of the earth
- Inner Core - The hottest point, it is 55o degrees and made from iron + nickel. It is a solid
- Outer Core - Has extreme tempretures, contains iron + nickel, contains the magnetic field. It is a liquid.
- The Crust - Layer we live on, cracked into plates. It is a solid.
- Mantle - Below the crust, it moves very slow due to convection currents which make the plates move. It is a solid
- Equakes
- Pyroclastic flow - Hot gases, ash, pumice and lava above 800 degrees Lahars - Volcanic debris saturated with water .
- Predicting equakes - Use radon detectors which are placed in the soil. Animals + fish act unusual.
- Tropical Storms
- Warm air from the storm & warm ocean higher than 27 degrees mix creating low pressure. Trade win ds in opposite directions make it spin.
- Air keeps rising and the pressure starts to decrease at higher altitudes. Air rises faster and faster to try & fill low pressure drawing more warm air from sea and sucking cooler air down
- As the storm travels over the ocean it collects warm moist air, the wind speed increases along with the air, The eye has low winds surrounded by a sinning vortex of high winds + heavy rainstorms.
- Air keeps rising and the pressure starts to decrease at higher altitudes. Air rises faster and faster to try & fill low pressure drawing more warm air from sea and sucking cooler air down
- Warm air from the storm & warm ocean higher than 27 degrees mix creating low pressure. Trade win ds in opposite directions make it spin.
- Pyroclastic flow - Hot gases, ash, pumice and lava above 800 degrees Lahars - Volcanic debris saturated with water .
- Global air circulation
- Air that is sinking towards the ground surface forms areas of high pressure, Winds on the ground move outwards from this area.
- Air that is rising from the ground surface forms area of low pressure on the ground.
- Winds on the ground are distorted by earths rotation. They curve from areas of low to high pressure.
- A natural event that threatens people or has the potential to cause damage, destruction and death.
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