Pearson Edexcel GCSE (9-1) Geography B (1GB0) · Spec 1.4, 1.5 and 1.6
Tropical cyclones
Read the notes, then try the questions. Each one is marked the moment you press Check, and shows the right answer and why.
Key ideas
- A tropical cyclone needs warm sea water (about 27 degrees Celsius or more) and a position roughly 5 to 30 degrees from the Equator. Warm, moist air rises, cools and condenses, and the Coriolis effect makes the storm spin.
- The eye is the calm centre. The eyewall around it has the strongest winds and heaviest rain.
- A cyclone weakens over land or cooler water because it loses the warm, moist air from the sea that gives it energy.
- Primary effects happen straight away, such as homes destroyed by wind and storm surge. Secondary effects follow later, such as disease after flooding.
- Preparation happens before landfall: forecasting, warnings, evacuation plans, shelters and defences. Response happens after landfall: rescue, aid and rebuilding.
Key terms
- Eye
- The calm centre of a tropical cyclone, with light winds and little cloud.
- Eyewall
- The ring of cloud around the eye with the strongest winds and heaviest rain.
- Storm surge
- A rise in sea level, caused by low pressure and strong winds, that floods the coast.
- Coriolis effect
- The effect of the Earth's spin that makes the storm rotate. It is too weak at the Equator for a storm to form.
- Vulnerability
- How badly a place is likely to be hurt. It depends on physical factors and social factors.
Common mistakes
- Saying a cyclone weakens over land mainly because of mountains. The main reason is that it is cut off from the warm, moist sea air.
- Saying vulnerability depends only on wealth. Physical factors such as a low-lying coast matter too, as do social factors such as warnings.
- Counting rescue, aid and rebuilding as preparation. They happen after the storm, so they are the response.
Exam tip
On Paper 1 an Explain one question for 3 marks is a point plus two developments, and Explain two for 4 marks needs two different ideas, each developed. Keep preparation (before landfall) and response (after landfall) apart, because mixing them loses marks.
Free practice questions
7 questions, 17 marks. Answer, then press Check. The marking guide explains how the marks are worked out. Nothing is saved.
- Question 1 · Multiple choice[1 mark]
At least how warm must the sea be for a tropical storm to form?
- Question 2 · Matching[4 marks]
Match each part of a tropical storm to what it is or does.
- Question 3 · True or false[4 marks]
Decide whether each statement about tropical storms is true or false.
1. The eye of a tropical storm is calm.
2. Tropical storms weaken when they move over land.
3. Tropical storms form on the Equator itself.
4. Tropical storms form all year round anywhere in the tropics.
- Question 4 · Put in order[1 mark]
Put the stages of tropical storm formation in order, starting with the warm ocean.
Use the arrows to put these in the right order, first at the top.
- 1The Coriolis effect makes the storm spin
- 2Pressure falls and winds are drawn in
- 3Warm ocean water heats the air above it
- 4Warm, moist air rises
- 5Water vapour condenses and releases heat
- Question 5 · Fill the gaps[2 marks]
Tropical storms weaken over ___ because they lose the warm, ___ air from the sea.
Word bank: land · dry · moist
- Question 6 · Sort into groups[4 marks]
Sort each action into preparation (before landfall) or response (after landfall).
Delivering food and water
Tracking the storm by satellite
Building shelters and evacuation routes
Rescue of trapped people
- Question 7 · Multiple choice[1 mark]
Which is the main reason a tropical cyclone weakens when it moves over land?