Paper 1 Section A - The Challenge Of Natural Hazards Flashcards
What is a natural hazard?
An a event that has the potential risk of damaging property or causing loss of life.
Without people there is no hazard.
How does urbanisation affect the risk of a natural hazard?
Urbanisation is the rise in the proportion of people living in urban areas (towns & cities).
Cities are more densely populated so are at more risk.
50% of the world lives in cities.
How does poverty affect the risk of a natural hazard?
LICs cannot combat natural hazards as well as HICs can due to the lack of infrastructure and healthcare.
In LICs the houses are built on unstable slopes so they are more prone to floods & landslides.
How does agriculture affect the risk of a natural hazard?
When a river floods it deposits fertile silt on its flood plain.
Floods are beneficial for farming but harmful to people.
How does climate change affect the risk of a natural hazard?
There is more energy in the atmosphere due to increased warmth.
This causes intense storms and hurricanes.
Climate change makes some countries to be more at risk of floods and some more prone to droughts and famines.
What is an earthquake?
A sudden and violent period of ground shaking.
Why might some earthquakes not occur at plate margins?
They may be caused by human activity such as underground mining or oil extraction.
Why is the oceanic crust dense and thin?
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Why is the continental crust thick and less dense?
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What is the evidence of plate tectonics moving?
The match in shape between the east coast of South America and the west coast of Africa.
There are similar patterns of rocks on both sides of the Atlantic.
What is a destructive plate margin?
Plates moving towards each other, causing volcanoes and earthquakes.
What is a constructive plate margin?
Two plates moving away from each other.
What is a conservative plate margin?
Plates moving alongside or against each other, causing earthquakes which are often severe.
Fill in the gaps:
At a destructive plate margin the ?? subducts under the ?? at the subduction zone. The plates are driven by ?? in the mantle. As the plates ? there is ? which results in lots of ??. The friction also melts the rock creating ?. This builds up creating a ?? with steep sides due to the lava being ?.
At a destructive plate margin the oceanic plate subducts under the continental plate at the subduction zone. The plates are driven by convection currents in the mantle. As the plates meet there is friction which results in lots of mini earthquakes. The friction also melts the rock creating magma. This builds up creating a composite volcano with steep sides due to the lava being thick.
Fill in the gaps:
At a constructive plate margin the two plates move ?, driven by ?? in the mantle. As the plates are ?? there are ? that occur. A ? appears and is ? by magma. The lava is very ? and forms a ?? which is very wide and flat.
At a constructive plate margin the two plates move apart, driven by convection currents in the mantle. As the plates are pulling apart there are earthquakes that occur. A gap appears and is filled by magma. The lava is very runny and forms a shield volcano which is very wide and flat.
