Geography

thin, solid rock of the earth's surface. Covered by oceans and part forms the land. It is about 5-55 km thick.

Below the crust. About 3000 km thick. Consists very hot semi-molten rocks (1600C) The lava of volcanoes comes from and goes through cracks in the Crust

Interior parts of the Earth. Very hot temperatures (2000C) Made out of NIFE (nickel+iron rocks) Very dense. Total radius is about 3500 km from the Earth's center

helps the crust of Earth float because the crust is less dense than the mantle.

Convection Currents

less dense then the oceanic place

Convection currents exist in the mantle. Heat flows from hotspots to cooler areas. The source of the heat driving the convection current is radioactive decay which is happening deep in the Earth.

crust breaks up into large segments

less dense rock (thickest crust up to 80km)

denser rock (thinner crust 10-12km)

• Constructive (Diverging/Splitting)
• Destructive (Converging/Collision)
• Conservative (Transform-Fault/Sliding)

When continental crust collides with oceanic crust

When two continental plates collide.

causes plates to get stuck

large super continent that scientists believe existed on Earth around 400 million years ago.

The shape of the continents fit together like a jigsaw

Same rock types and identical plant and animal fossils of the same age have been found in rocks in Africa and South America

• Distribution of animals proves that places have separated.
• Example : Africa - Cheetah, South America - Jaguar

Types of rocks found on each continent today show similar strata and ages. Mountain range on the coast of West Africa disappear then suddenly reappear again on the coast of South America.

• Richter Scale
• Mercalli Scale

The strength or magnitude of an earthquake is measured by this. Measurements are logarithmic, this means that each whole number step represents a ten-fold increase in measure amplitude. This means a magnitude 7 earthquake is 10 times larger than a 6 and 100 times larger than a magnitude 5.

(Size of wave) enables us to record the amount of energy

recording device that measures earthquakes

Observational scale, assesing the damage cause from I to XII

• Socio-Economic Factors - Population Density, Wealth of the area, Education of Population, Preparation
• Physical Factors -Type of soil may mean liquefaction occurs, Proximity to coast, tsunami risk, Danger of landslide

• Prediction
• Preparation

• Animal behavior
• Water levels in wells drop or rise
• Build up of electro-magnetic radiation can be monitored

States that along faults that are seismically active, the regions that are more likely to experience earthquakes in the near future are those that have not shown seismic activity in some time.

• emergency supplies
• food
• water
• portable toilets

• Building Regulations
• Education
• Rescue Teams
• Civil Defense Organization

Buildings need to be made of reinforced concrete.

A height limit should be placed on buildings in places that have sandy soils.

Land use zoning: Make it ilegal to build in areas that are unsafe.

Drills carried out by an institution

Simulations carried out by a whole area

Ready for emergencies best provided in EMDCs

• 
• Permian-225 million years ago
• Triassic - 200 million years ago
• Jurassic - 135 million years ago
• Cretaceous - 65 million years ago

Occur along plate margins (where plates meet). Happens when plates move past, towards or away from each other the movement is not smooth. Occurs when the build up of pressure (plates that get stuck and the pressure builds up) is released.

The point where the earthquake starts

The point at ground level directly above the focus

The whole seismometer moves as the earth is attached to shakes but the heavy mass does not move because of its inertia. The recording device measures how far the rest of the seismometer has moved with respect to the mass.

• Direct - effects that are caused by the earthquake
• Indirect - Events set of as a consequence of the earthquake (there is a time delay)

• Building collapses
• Subsidence
• Liquefaction

downwards motion of earth's surface

when ground behaves like liquid and so loses its ability to carry weight

• Fires
• Tsunamis
• Landslides
• Epidemics

• Constructive
• Subduction Zone
• Continental Collision
• Consevative

• Constructive
• Subduction Zone

• Subduction Zone
• Continental Collision

Subduction Zone

Constructive