Edexcel GCSE Geography: Hazardous Environments

Key Takeaways: Hazardous Environments (GCSE Geography Revision)

1. Types of Hazards

• Definitions:
  • Hazard: Environmental event threatening damage (e.g., earthquakes).
  • Natural Disaster: Hazard causing significant destruction (e.g., >10 deaths).
• Categories:GeologicalClimaticBiologicalTechnologicalEarthquakesStormsFiresNuclear explosionsVolcanoesFloodsPestsPollution

Key Rule: Disasters require international criteria (e.g., state of emergency, 100+ injured).

2. Earthquakes

• Causes: Occur at destructive (subduction) and conservative (sliding) plate margins.
• Characteristics:
  • Focus: Underground origin.
  • Epicentre: Surface point above focus.
  • Damage factors: Depth of focus, rock type (soft rocks worsen shaking).
• Measurement:
  • Richter Scale: Logarithmic; Energyn=30×Energyn−1Energyn​=30×Energyn−1​.
  • Mercalli Scale: Damage/experience-based (e.g., 5 = objects fall; 10–12 = buildings collapse).

Example: 2011 Tōhoku earthquake (Japan) triggered a tsunami due to undersea focus.

3. Volcanoes

• Distribution: Mostly at plate margins; hotspots (e.g., Hawaii) form within plates.
• Hazards:
  • Lava flows (slow-moving but destructive).
  • Pyroclastic flows (450 mph, 1000°C).
  • Ash clouds (respiratory issues, roof collapses).
• Eruption Types:
  • Constructive margins: Gentle eruptions (e.g., Iceland).
  • Destructive margins: Violent eruptions (e.g., Mount St. Helens).

Tip: Compare shield vs. composite volcanoes for exam questions.

4. Tropical Storms

• Formation: Requires sea temps >27°C; stages include warm air rising and spiralling winds.
• Characteristics:
  • Eye: Calm centre.
  • Eyewall: High winds (55–118 km/h).
  • Storm surges: Coastal flooding.
• Classification: Saffir-Simpson Scale (Category 5 = >250 km/h winds, catastrophic damage).

Case Studies:

• LIC: Cyclone Nargis (Myanmar, 2008) – 140,000 deaths, poor preparedness.
• HIC: Hurricane Katrina (USA, 2005) – $98bn damage, evacuation failures.

5. Why Live in Hazard Zones?

• Reasons:
  • Fertile soils (volcanic ash in Indonesia).
  • Economic opportunities (tourism in Iceland).
  • Lack of resources to relocate (LICs like Haiti).
  • Perceived rarity of disasters.

Example: Naples, Italy, near Mount Vesuvius – high population despite eruption risks.

6. Mitigation Strategies

• Prediction:
  • Volcanoes: Monitor earthquakes, gas emissions.
  • Earthquakes: Limited warning; focus on building codes (e.g., Japan’s earthquake-proof structures).
  • Tropical Storms: Satellite tracking (e.g., NOAA).
• Preparation:
  • LICs: Storm shelters, community drills.
  • HICs: Levees (New Orleans), early-warning systems.

Exam Tip: Compare prediction (HICs use tech; LICs rely on aid) and preparation (HICs invest in infrastructure).

7. Impacts & Responses

• Primary Effects: Immediate damage (e.g., deaths, destroyed homes).
• Secondary Effects: Long-term consequences (e.g., economic slump, disease).
• Responses:
  • Short-term: Emergency aid (e.g., 2004 Asian tsunami – $14bn relief).
  • Long-term: Rebuilding (e.g., Banda Aceh’s tsunami warning system).

Case Study: 2004 Asian Tsunami – 230,000 deaths; global aid coordination.

8. Exam Techniques

• Case Studies: Revise one tectonic (e.g., Japan earthquake) and one climatic (e.g., Katrina) event.
• Compare HIC vs. LIC: Use Cyclone Nargis (LIC) and Katrina (HIC) for impacts/responses.
• Math Skills: Calculate population density: Density=PopulationArea (km2)Density=Area (km2)Population​.

Top Tips:

• Use PEEL structure (Point, Evidence, Explain, Link).
• For 9-mark questions, include 3 detailed comparisons.

50 GCSE Geography Questions on Hazardous Environments

Section A: Short Answer Questions (1–2 marks)

1. Define the term ‘natural hazard’.
2. What criteria must be met for a disaster to be listed on the International Disaster Database?
3. Name two geological hazards.
4. What is the epicentre of an earthquake?
5. State two differences between the Richter and Mercalli scales.
6. Why do earthquakes at destructive plate margins tend to be more frequent?
7. What is a tsunami?
8. Name two hazards caused by volcanic eruptions.
9. Why do tropical storms form over oceans with temperatures above 27°C?
10. What is the ‘eye’ of a tropical storm?
11. Identify the wind speed range for a Category 4 tropical storm on the Saffir-Simpson scale.
12. Name one method used to monitor tropical storms.
13. What is population density?
14. Why might people live near volcanoes despite eruption risks?
15. Give two examples of short-term responses to earthquakes.

Section B: Case Study Questions (3–4 marks)

16. Describe the social impacts of Cyclone Nargis (2008) in Myanmar.
17. Explain why Hurricane Katrina (2005) caused severe flooding in New Orleans.
18. Outline two long-term responses to the 2004 Asian tsunami.
19. Compare the economic impacts of Cyclone Nargis (LIC) and Hurricane Katrina (HIC).
20. Why did the 2004 tsunami cause such high casualties in Banda Aceh?

Section C: Data Interpretation (4–6 marks)

21. Study Figure 3.1 (tectonic plates). Explain why earthquakes occur at conservative margins.
22. Using Figure 3.5 (Saffir-Simpson scale), describe how damage increases with storm category.
23. Analyse Figure 3.7 (population density). Why do densely populated areas overlap with hazard zones?
24. Calculate population density for a city with 2 million people and an area of 500 km². Use Density=PopulationAreaDensity=AreaPopulation​.
25. Interpret Figure 3.9. What type of hazard is shown, and how long did it take to move through Honduras?

Section D: Extended Response (6–9 marks)

26. Explain why earthquakes are difficult to predict.
27. Discuss how volcanic eruptions can have both positive and negative impacts.
28. Evaluate the effectiveness of preparation strategies for tropical storms in HICs vs. LICs.
29. ‘The impacts of natural disasters are always worse in LICs.’ To what extent do you agree?
30. Analyse how human activity can increase the risk of hazards becoming disasters.

Section E: Skill-Based Questions

31. Sketch and label the structure of a tropical storm.
32. Draw a annotated diagram of a destructive plate margin.
33. Map the global distribution of volcanoes using Figure 3.3.
34. Create a flowchart showing the stages of tropical storm formation.
35. Design a poster advising communities on earthquake preparedness.

Section F: Mathematical Questions

36. An earthquake measures 6 on the Richter scale. Calculate how much more energy it releases than a magnitude 5 quake. Use Energyn=30×Energyn−1Energyn​=30×Energyn−1​.
37. Convert 215 km/h (Cyclone Nargis) to mph (1 km ≈ 0.62 miles).
38. A volcanic ash cloud spreads 150 miles from a volcano. Convert this distance to kilometres.
39. If a tsunami travels at 500 km/h, how long would it take to reach a coast 1000 km away?
40. Calculate the storm surge height for a Category 5 storm using Figure 3.5.

Section G: Terminology & Concepts

41. Define ‘pyroclastic flow’.
42. What is geothermal energy, and how is it linked to volcanic areas?
43. Explain the term ‘storm surge’.
44. Differentiate between primary and secondary impacts of hazards.
45. What is a ‘hotspot’ volcano?

Section H: Comparison Questions

46. Compare the characteristics of shield and composite volcanoes.
47. Contrast earthquake preparation strategies in Japan (HIC) and Nepal (LIC).
48. How do the causes of floods differ from those of tropical storms?
49. Compare the roles of satellites and radar in monitoring weather hazards.
50. Why might tectonic hazards have more predictable patterns than climatic hazards?

Detailed Answers

1. Natural hazard: An event from environmental processes that threatens or causes damage to people, property, or settlements (e.g., earthquakes).
2. Criteria: ≥10 deaths, ≥100 injured, state of emergency declared, or international assistance requested.
3. Geological hazards: Earthquakes, volcanic eruptions.
4. Epicentre: The point on Earth’s surface directly above the earthquake’s focus.
5. Richter vs. Mercalli:
   • Richter measures energy released (logarithmic scale: Energyn=30×Energyn−1Energyn​=30×Energyn−1​).
   • Mercalli measures observed damage/experience (e.g., Level 5 = objects fall).
6. Destructive margins: Intense pressure from subduction causes frequent seismic activity.
7. Tsunami: Large ocean waves triggered by undersea earthquakes/volcanic eruptions.
8. Volcanic hazards: Lava flows, ash clouds, pyroclastic flows.
9. Warm oceans: Provide energy via evaporation, fueling storm development.
10. Eye: Calm, low-pressure centre with light winds and no rain.
11. Category 4 winds: 210–249 km/h.
12. Monitoring method: Satellites, radar, or weather stations.
13. Population density: Number of people per km² (Density=PopulationAreaDensity=AreaPopulation​).
14. Reasons: Fertile soils, economic opportunities, lack of relocation options.
15. Short-term responses: Emergency shelters, rescue operations.

Section B: Case Study Questions (3–4 marks)

16. Social impacts of Cyclone Nargis (2008):

• At least 140,000 deaths.
• 3 million homeless; 95% of homes destroyed.
• Drinking water polluted, leading to disease outbreaks.

17. Hurricane Katrina flooding in New Orleans:

• Storm surge (8.5 m) overwhelmed poorly maintained levees.
• 80% of the city flooded due to low elevation and subsidence.

18. Long-term responses to 2004 tsunami:

• Rebuilding projects (e.g., £40 million spent in Sri Lanka/Indonesia).
• Installation of Indian Ocean tsunami warning system (2006).

19. Economic impacts comparison:

• Cyclone Nargis (LIC): $10 billion rebuild cost; reliance on foreign aid.
• Hurricane Katrina (HIC): $98 billion rebuild cost; funded domestically.

20. 2004 tsunami casualties in Banda Aceh:

• Proximity to epicentre (first hit).
• Lack of warning systems and evacuation plans.

Section C: Data Interpretation (4–6 marks)

21. Earthquakes at conservative margins:

• Plates slide past each other, causing friction and sudden jerks (e.g., San Andreas Fault).

22. Saffir-Simpson damage escalation:

• Category 1: Minor tree damage → Category 5: Catastrophic building destruction.
• Storm surge increases from 1.0 m (Cat 1) to >5.7 m (Cat 5).

23. Dense populations in hazard zones:

• Economic opportunities (e.g., farming on volcanic soils).
• Urbanisation inertia (e.g., Tokyo near tectonic boundaries).

24. Population density calculation:
    Density=2,000,000500=4000 people/km2Density=5002,000,000​=4000 people/km2
25. Figure 3.9 interpretation:

• Hazard: Tropical storm.
• Duration in Honduras/El Salvador/Guatemala: 3 days (inferred from date labels).

Section D: Extended Response (6–9 marks)

26. Earthquake prediction challenges:

• No reliable precursors (unlike volcanoes).
• Focus is underground; limited technology to monitor plate movements.

27. Volcano impacts:

• Negative: Destruction (e.g., Pompeii), ash disrupting air travel.
• Positive: Fertile soils (e.g., Sicily), geothermal energy (e.g., Iceland).

28. Storm preparation effectiveness:

• HICs: Advanced tech (e.g., NOAA satellites), levees (e.g., New Orleans).
• LICs: Reliance on aid (e.g., Myanmar’s delayed Cyclone Nargis response).

29. Impacts worse in LICs?

• Agree: Poor infrastructure, limited healthcare (e.g., 140,000 deaths in Myanmar vs. 1,800 in USA).
• Disagree: HICs face high economic costs (e.g., Katrina: $98 billion).

30. Human activity increasing disaster risk:

• Deforestation → landslides (e.g., Haiti).
• Urbanisation in floodplains → exacerbated flooding (e.g., Bangladesh).

Section E: Skill-Based Questions

31. Tropical storm structure:

• Label: Eye (calm), eyewall (high winds), rainbands (heavy rain).

32. Destructive plate margin diagram:

• Annotate: Subduction zone, magma rising, volcanic arc.

33. Volcano distribution map:

• Plot: Pacific Ring of Fire, mid-Atlantic Ridge, hotspots (e.g., Hawaii).

34. Tropical storm formation flowchart:

• Stages: Warm ocean → rising air → spiralling winds → eye formation.

35. Earthquake preparedness poster:

• Tips: Secure furniture, emergency kits, evacuation drills.

Section F: Mathematical Questions

36. Richter scale energy increase:
    Energy6=30×Energy5Energy6​=30×Energy5​ (30x more energy).
37. Cyclone Nargis wind speed in mph:
    215 km/h×0.62=133.3 mph215 km/h×0.62=133.3 mph
38. Ash cloud distance in km:
    150 miles×1.61=241.5 km150 miles×1.61=241.5 km
39. Tsunami travel time:
    Time=1000500=2 hoursTime=5001000​=2 hours
40. Category 5 storm surge:
    >5.7 m>5.7 m (from Saffir-Simpson scale).

Section G: Terminology & Concepts

41. Pyroclastic flow: Superheated gas/ash cloud (450 mph, 1000°C).
42. Geothermal energy: Heat from magma used for power (e.g., Iceland).
43. Storm surge: Sea rise due to low pressure and high winds.
44. Primary vs. secondary impacts:

• Primary: Immediate damage (e.g., collapsed buildings).
• Secondary: Long-term effects (e.g., economic recession).

45. Hotspot volcano: Forms over mantle plumes (e.g., Hawaii).

Section H: Comparison Questions

46. Shield vs. composite volcanoes:

• Shield: Gentle eruptions (basaltic lava), e.g., Mauna Loa.
• Composite: Violent eruptions (viscous lava), e.g., Mount Fuji.

47. Earthquake prep: Japan vs. Nepal:

• Japan: Earthquake-proof buildings, drills.
• Nepal: Limited funds, reliance on NGOs.

48. Floods vs. tropical storms:

• Floods: Caused by heavy rain/river overflow.
• Tropical storms: Driven by warm ocean temps.

49. Satellites vs. radar:

• Satellites: Track cloud patterns globally.
• Radar: Monitors local precipitation movement.

50. Tectonic vs. climatic predictability:

• Tectonic: Follow plate boundaries (predictable zones).
• Climatic: Influenced by variable weather systems.