STRUCTURE OF THE EARTH
CRUST - thin solid layer of rock which floats on top of the mantle.
MANTLE - thickest layer within the Earth composed of semi-molten rock.
OUTER CORE - layer of molten iron and nickel which surrounds the inner core.
INNER CORE - ball of solid iron, nickel and radioactive material which generates heat.
TYPES OF PLATE BOUNDARY - Conservative
Two plates moving past each other causing earthquakes
Oceanic plate is subducted beneath the continental plate = earthquakes and volcanic erupstions.
Two plates moving apart resulting in the creation of new land.
Two continental plates moving towards each other resulting in the formation of mountains.
CONE VOLCANO - lava is very viscous so creates a steep triangular volcano which experience volcanic eruptions.
SHIELD VOLCANO - lava is very runny so covers large areas, resulting in large volcanoes with gently sloping sides.
ACTIVE - likely to erupt again in the near future.
DORMANT - unlikely to erupt but does have the potential to erupt again.
EXTINCT - volcanoes that are extremely unlikely to erupt again.
MAGNITUDE - the strength of earthquakes is measured on the Richter Scale.
MANAGING THE IMPACTS
- Emergency plans: many countries will train their emergency services so they know how to respond to a tectonic disaster.
- Education: MEDCs educate their population so that they do not panic during a disaster.
- Buildings: MEDCs design buildings to withstand earthquakes using shock absorbers, cross-bracing. counterweights and reinforced windows.
LIVING WITH TECTONIC HAZARDS
WHY DO PEOPLE LIVE NEAR TECTONIC HAZARDS?
- Fertile Soil: (VOLCANOES ONLY) ash adds nutrients to the soil which improves farming conditions.
- Lack of Risk: many either do not understand the risk or believe there is no risk.
- No Choice: many cannot afford to move or have nowhere else to move.
- Family Ties: people are emotionally attached to the area.
- Economic Activity: the scenic lanscape attracts tourists which brings money.