The challenge of natural hazards Flashcards
what is a natural hazard?
natural event that has potential to cause damage, destruction and death
what are the different factors which affect hazard risk?
Urbanisation- densely populated areas are at greater risk of natural hazards
Level of economic development- Hics are better equipped to cope with natural hazards than Lics
what are the primary effects of an earthquake?
> People killed and injured.
buildings and homes destroyed.
Bridges, roads, ports and railways destroyed.
Gas and water pipes and electric cables are broken.
what are secondary effects of an earthquake?
> The economy slowing due to money being spent repairing damage and business activity reduced.
Blocked transport infrastructure restricts emergency services from rescuing people.
Burst water pipes lead to a shortage of fresh water, poor sanitation and illness.
what are primary effects of a volcanic eruption?
> People injured or killed
Farmland and buildings destroyed
No air travel due to ash
what are the secondary effects of a volcanic eruption?
> Emergency services struggle to a arrive
Ash provides fertile soil
Lahars
what is a constructive plate boundary?
when two plates move away from each other.
how does a destructive plate boundary cause volcanos?
when an oceanic and continental plate move towards each other the denser, heavier oceanic plate subducts. Oceanic plate heats due to the mantle and becomes molten magma. This may be forced to the earth causing a volcanic eruption.
what is a conservative plate boundary?
when two plates slide past each other
how is an earthquake caused in a destructive plate margin?
plates lock
pressure builds
Crust fractures
seismic waves
What are convection currents?
When heated molten rock rises, the tectonic plate on top of the mantle drags with it
