Natural Hazards

Question 1

What is a natural hazard?

Answer 1

A naturally occurring event that has the potential to cause harm or destruction

Question 2

Hazard risk

Answer 2

The probability the natural hazard will impact a population

Question 3

How do tectonic plates move?

Answer 3

1) core heats up magma in mantle
2) hot magma is less dense than surroundings so rises
3) when magma reaches near crust it cools, becomes more dense, and sinks to the bottom
4) the plates that lie on top are pushed by the convention currents

Question 4

Constructive plate margins

Answer 4

-when two plates are pulled apart, magma rises between the plates
-volcanos occur where lava pours out
-earthquakes occur as plates vibrate
-continental or oceanic crust

Question 5

Destructive plate margins

Answer 5

-as two plates move towards each other, the denser crust is subducted below
-friction causes earthquakes
-oceanic crust is pulled deeper into the mantle and magma rises as volcanoes

Question 6

Conservative plate margins

Answer 6

-parallel plates move in opposite directions at different speeds
-friction builds up so plate eventually moves in a sudden jault, causing an earthquake

Question 7

Why live in hazardous places?

Answer 7

-nutrient rich, fertile soil
-well developed from tourism
-hazard monitoring
-poverty

Question 8

Hazard management

Answer 8

-Monitoring (detecting physical changes eg. Vibrations)
-Predicting (using monitoring and historical trends to predict when it will occur)
-Protecting (increasing resistance eg. Shock absorbers on buildings)
-Planning (having systems in place eg. Evacuation routes)

Question 9

Causes of tropical storms

Answer 9

-sea temp of around 26°c
-unstable air pressure
-5° to 30° either side of equator
-fairly strong wind
-water must be 50m deep

Question 10

Formation of tropical storms

Answer 10

1) warm, moist air rises, leaving lower pressure below, causing warm air from surroundings to move into this low pressure area
2) warm air condenses into large clouds
3) whole system starts to spin due to the Coriolis effect
4) constant additions of energy from the warm air and sea
5) the storm develops an eye (an area of extremely low pressure) and an eye wall (the most powerful area of the storm)
6) when the storm reaches the coast, the low pressure and high winds cause a storm surge to be pushed on land. On land there is no longer a supply on energy so the storm dissipates