Geography: Tectonic Hazards

Plate Margins
1. Destructive
  1. Where two plates move towards each other. The denser plate subducts beneath the other, friction causes it to melt and become molten magma. Also responsible for earthquakes.
2. Constructive
  1. When two plates are moving away from each other, magma rises from the mantle to fill the gap and cools creating new crust.
3. Conservative
  1. Where two plates are moving sideways past each other or are moving in the same direction but at different speeds. Crust isn't created or destroyed.
Earthquakes
1. Caused when two plates collide. Tensions build up when one plate gets stuck as it's moving down past the other in the mantle. Can occur at all plate margins.
2. LIC: Haiti Earthquake - 2010
  1. Magnitude - 8.8
  2. Effects
    1. 500 killed, 12,00 injured 500,000 homes destroyed
    2. Santiago's airport was slightly damaged.
    3. Several Pacific countries were hit by the tsunami.
  3. Responses
    1. A national telethon raised $60million.
    2. After an earthquake in 1960, all new buildings were built to withstand earthquakes.
3. HIC: Chile Earthquake - 2010
  1. Effects
    1. 1.3million made homeless 8 hospitals destroyed
    2. 2million left with no food/water, serious looting.
    3. Many dead bodies in hot temperatures became a health hazard.
  2. Magnitude - 7.0
  3. Responses
    1. Route 5 was fixed 24 hours later
    2. After one year, there were still 1,300 camps for the homeless.
Volcanoes
1. Destructive plate margin
  1. Oceanic plate goes under the continental plate.
  2. Oceanic plate moves into the mantle, melted and destroyed. Magma forms then rises through cracks in the crust. Magma (Lava) erupts onto surface.
2. Constructive plate margin
  1. Magma rises up into the gap created by the plates moving apart.
3. When a volcano erupts, it emits lava and gases. Some emit ash, block out the sun and form pyroclastic flows.
Living with Tectonic Hazards
1. Why people live in areas at risk?
  1. Don't want to leave their families/friends
  2. Soil around volcanoes is fertile because of the minerals from the ash and lava.
  3. Employed in the area
2. Management Reduces the Effects
  1. Montoring
    1. Seismometers monitor earth movements, and can be used in early warning systems.
  2. Prediction
    1. By monitoring the movement of tectonic plates. Gives people time if they need to evacuate - less deaths/injuries
  3. Protection
    1. Buildings designed to withstand earthquakes
    2. Automatic shut-off switches are fitted to turn off electricity supplies to prevent fires.
    3. Buildings can be strengthened so they're less likely to collapse.
  4. Planning
    1. Emergency services can train and prepare for disasters
    2. Governments can plan evacuation routes to get people out of dangerous areas quickly and safely.
    3. People can be educated so that they know what to do if a disaster happens.
Natural Hazard
1. A natural hazard is a natural process which could cause death, injury or disruption to humans.
2. Geological Hazard
  1. Caused by land and tectonic processes e.g volcanoes and earthquakes.
3. Meteorological Hazard
  1. Caused by weather and climate e.g tropical storms.

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Geography: Tectonic Hazards

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	Created by Blerta Morina about 5 years ago