Storm Hazards

Question 1

What are tropical storms?

Answer 1

Tropical storms are huge spinning storms with strong winds and torrential rain.

Question 2

Where do tropical storms develop?

Answer 2

They develop over warm water. As warm, moist air rises and condenses, it releases energy that increases wind speed.

Question 3

Name four conditions needed for a tropical storm to form?

Answer 3

1. A disturbance near the sea surface that triggers the storm (e.g. an area of low pressure)
2. Sea water that’s above 27 degrees, so lots of water will evaporate.
3. Convergence of air in the lower atmosphere - either within the ITCZ or along the boundary between warm and cold air masses. This forces warm air to rise.
4. A location at least 5 degrees from the Equator. They don’t form 0-5 degrees either side of the Equator because the Coriolis effect isn’t strong enough to make them spin.

Question 4

What is the Coriolis effect?

Answer 4

The Coriolis effect is a force caused by the Earth’s rotation. It deflects the path of winds but its weak at the Equator.

Question 5

What are tropical storms called in the Caribbean Sea?

Answer 5

Hurricanes

Question 6

What are tropical storms called in the Bay of Bengal?

Answer 6

Cyclones

Question 7

What are tropical storms called in the China Sea and Northern Australia?

Answer 7

Typhoons

Question 8

Why do tropical storms lose strength when they go over land?

Answer 8

When they move over land their supply of warm, moist air is cut off.

Question 9

In which direction do the trade winds move the hurricanes?

Answer 9

They move west across the Atlantic Ocean due to the easterly winds in the tropics.

Question 10

In which direction do the tropical storms spin?

Answer 10

They spin anticlockwise in the northern hemisphere, and clockwise in the southern hemisphere.

Question 11

What is in the centre of the storm?

Answer 11

An area of low pressure called the eye. Rising air spirals around the eye in the eyewall, causing strong winds.

Question 12

What is at the top of the storm?

Answer 12

There is an outflow of moisture laden air, so cloud cover extends for a long distance either side of the eye.

Question 13

What are storm classified using?

Answer 13

They are classified using the Saffir Simpson Scale, which is based on wind speed. Category 5 is the strongest.

Question 14

What does the Saffir Simpson Scale estimate?

Answer 14

It also estimates how much damage a storm of a given magnitude will do.

Question 15

Why is it hard to determine when or where storms will happen?

Answer 15

There are lots of factors that affect where or when a tropical storm will form and where it will hit land, so the hazards created by storms are largely irregular, they follow no clear spatial or temporal pattern.

Question 16

Name 5 hazards a storm can cause?

Answer 16

High Winds
Storm Surges 
Heavy Rain
Flooding 
Landslides

Question 17

Name three social impacts storms can cause?

Answer 17

People may drown, or be injured or killed by debris that’s blown around or carried in flood water.
Houses are destroyed, so people are left homeless.
Electricity cables are damaged and supplies cut off.

Question 18

Name two political impacts storms can cause?

Answer 18

People may blame the authorities for shortages of food, water and energy, leading to conflict and unrest.
Expensive repairs to buildings, infrastructure which limits the amount of money that can be spent on development.

Question 19

Name two environmental impacts storms can cause?

Answer 19

Beaches are eroded and coastal habitats are damaged.

Environments are polluted, e.g. by salt water, oil and chemicals spilled from damaged factories.

Question 20

Name two economic impacts storms can cause?

Answer 20

Buildings and infrastructure cost a huge amount to rebuild.

Businesses are damaged or destroyed do they cant trade.