natural hazards Flashcards
Where are the majority of earthquakes found?
plate boundaries, e.g west of South America
Where are the majority of volcanoes found?
plate boundaries
what are the 3 types of plate boundaries?
- constructive
- destructive
- conservative
How is an Earthquake formed at a destructive plate margin?
1) 2 plates move towards each other
2) the denser plate (oceanic) will subduct under the lighter plate (continental) into the mantle.
3) friction between the 2 plates cause pressure to build up as they try to move.
4) Eventually pressure is released causing an earthquake.
How is a volcano formed at a destructive plate margin?
1) As the oceanic plate is forced down into the mantle it melts and magma created rises up forming a volcano.
2) a deep ocean trench and fold mountain are formed.
How are volcanos formed at constructive plates boundaries?
1) 2 plates move apart.
2) as the plates separate magma is forced its way through the gap formed.
3) on reaching the surface magma erupts and volcanos are formed.
How are earthquakes formed at constructive plates boundaries?
1) when magma reaches the crust it generates small earthquakes.
How are earthquakes formed at conservative plate margins?
1) 2 plates move past each other, either in opposite or the same direction.
2) friction and pressure is caused at this plate boundary causing large earthquakes.
Why are no volcanos formed at conservative plate margins?
because no magma reaches the surface.
Give 8 reasons why people choose to live in hazardous areas.
1) tourism
2) family
3) poverty
4) valuable minerals to mine
5) people want to live in cities
6) confidence in MPPP
7) lack of education
8) fertile soils for agriculture
what date was Haiti earthquake?
12 January, 2010
what was the magnitude of the Haiti earthquake?
7.0
what type of plate margin occurred at Haiti?
conservative
What time did Haiti earthquake hit?
4.53pm
Give 4 primary effects of Haiti?
1) 316,000 died
2) 1 million left homeless
3) 3 million effected by the earthquake.
4) 4,000 inmates escaped
Give 4 secondary effects of Haiti?
1) 1 in 5 people lost their jobs.
2) diseases such as cholera due to bodies.
3) difficult to get out due to airport issues
5) large number of deaths meant full hospitals
Give 4 immediate responses of Haiti?
1) 115,00 tents & 1 million tarpaulin shelters.
2) $100 million in aid given by the USA
3) healthcare supplied to limit disease.
4) 4.3 million provided with food rations.
Give 3 long-term responses of Haiti?
1) 98% of rubble on roads hadn’t been cleared restricting access.
2) water & sanitation eventually supplied for 1.7 million people.
3) after 1 year 1 million still homeless.
what happens at high pressure?
- air sinking
- no clouds
- calm clear weather
What happens at low pressure?
- air rises
- clouds cooling & condensing leading to rain.
- stormy cloudy weather.
what is the inter tropical convergence zone?
- a band of low pressure
- a point where the 2 Hadley cells meet.
How do tropical storms form?
- ocean temperatures from to in excess 27 degrees celsius.
- when these conditions are in place rapid rates of evaporation transfer high quantities of warm water vapour into the air
- ## the storm develops an eye at the centre where air decides rapidly.
