Tectonic hazards
Connect plate structure and movement to earthquakes and volcanoes, then compare impacts, responses and risk management.
Exam scope and assessment notes
Cambridge IGCSE (9–1) Geography 0976, 2027–2029 syllabus, Topic 4. The syllabus does not prescribe one universal set of named detailed specific examples: centres select places suited to their learners. Sixteen optional StudyForA evidence packs now cover all sixteen example objectives, but the centre's choices are unconfirmed. Match each pack to your centre's chosen place and replace any mismatch before treating the course as complete. Original StudyForA explanations and self-check practice are not Cambridge papers, official grades or teacher-marked coursework. Map, graph and written answers are not automatically assessed. Paper 4 practice uses supplied or invented data and cannot certify safe fieldwork, equipment use or real data collection. Centre-set coursework and specialist teacher review remain pending. This is the separate 9–1 qualification. Cambridge limits this 9–1 syllabus to certain zones: in June it is available in Administrative Zone 3 and for centres in Oman and the UAE; in November it is available in Zone 3 only. Confirm the exam series and entry with your centre. Cambridge also says an entry cannot be switched from 9–1 to A*–G after the entries deadline.
Before you begin
- No previous Geography course is assumed. Use the supplied map, data or scenario; distinguish observation from explanation and support conclusions with evidence.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
At a destructive plate boundary, what may happen to the denser oceanic plate?
What you will learn
- Describe Earth's layers, plate locations and boundary movement
- Explain earthquake and volcanic processes and hazards
- Compare primary and secondary impacts and event measures
- Evaluate preparedness, response and named earthquake/eruption examples
Plate movement concentrates tectonic activity
The inner core, outer core, mantle and crust have different properties; the lithosphere includes the crust and rigid uppermost mantle and is divided into plates. Plates move slowly over the underlying mantle. Divergent boundaries move apart, destructive convergent boundaries involve subduction, collision boundaries bring continents together, and conservative boundaries slide past.
Earthquakes occur when stress is released along faults; seismic waves radiate from a focus, with the epicentre at the surface above it. Volcanoes form through different pathways: subduction can produce viscous magma and explosive eruptions, while some divergent boundaries and hotspots produce more fluid lava.
Hazards vary in speed, spread and frequency
Volcano features include magma chamber, vent, crater and secondary cone. Composite cones, shield volcanoes and cinder cones differ in shape and eruption products. Volcanoes may be active, dormant or extinct, but classifications depend on evidence and definitions.
Tectonic hazards include shaking, surface rupture, lava, ash, tephra, lahars, pyroclastic flows and toxic gases. Compare speed, size, frequency and spread. Moment magnitude and Richter scales describe earthquake magnitude using different methods; Mercalli describes observed intensity/damage. VEI classifies explosive eruption size, not every impact.
Risk depends on exposure and capacity to respond
People may live near hazards because of fertile soil, jobs, minerals, tourism, family ties or lack of alternatives. Impacts can be primary (directly caused) or secondary (following disruption), and social, economic and environmental. Responses include immediate rescue and relief as well as long-term recovery.
Monitoring and prediction cannot guarantee exact forecasts. Protection, planning, education, building design and emergency systems may reduce risk. Evaluate access, affordability, governance and who is protected. Use one named earthquake and one named eruption chosen for the course, with causes, impacts, responses and management.
Pause and explain
Why can a smaller earthquake cause severe losses in one city and fewer in another?
Worked example
A magnitude 6 earthquake occurs in two places. One has far greater losses. Give three geographic reasons the impacts may differ.
Show the worked solution
- Magnitude is not the same as exposure or vulnerability.
- Population density, building quality and depth/distance from the epicentre may differ.
- Preparedness, emergency access, time of day and secondary hazards also affect outcomes.
Answer Losses may be greater where more people and vulnerable buildings are exposed, or where preparedness and emergency access are weaker. Magnitude alone does not determine impacts.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
An earthquake's epicentre is 15 km from a city; another is 120 km from a smaller town. State one likely reason the first location could face stronger shaking and two factors that would still affect damage.
Give me a hint
Use distance to explain possible shaking, then separate exposure and vulnerability.
Compare my reasoning
- The city is much closer to the epicentre, which may mean stronger shaking, all else equal.
- Population density and building design affect exposure and vulnerability.
- Preparedness and local ground conditions can also change impacts.
The closer city may experience stronger shaking, but damage also depends on building quality, population exposure, ground conditions and preparedness.
Look for these in your work
- Distance used cautiously
- Two impact factors stated
- Hazard separated from vulnerability
A volcano has slow-moving lava and ash that can travel much farther. Explain why one hazard may allow evacuation while another threatens wider areas quickly.
Give me a hint
Compare speed and spread rather than treating all volcanic hazards alike.
Compare my reasoning
- Slow lava may allow more warning time where routes remain open.
- Ash can be carried far by wind and affect health, transport and water over a wide area.
- Pyroclastic flows or lahars can move rapidly and leave little response time.
The risks differ by speed, direction and area affected: slow lava may permit evacuation, while ash can spread widely and fast flows may allow little warning. Local monitoring and terrain matter.
Look for these in your work
- Speed compared
- Spread compared
- Response implications linked
A government must divide a limited budget between earthquake-resistant schools and a monitoring network. Recommend a priority and state the evidence needed to justify it.
Give me a hint
Compare probability, exposed population, warning value and whether the measure reduces vulnerability.
Compare my reasoning
- Safer schools can reduce building collapse and protect people in a high-occupancy setting.
- Monitoring may improve awareness or warning for some hazards but cannot reliably predict every earthquake.
- Use hazard maps, school occupancy, building audits, costs and warning lead time to decide.
A defensible choice depends on local risk: retrofit highly exposed unsafe schools where collapse risk is high, and use monitoring as part of a wider system. Hazard, building and cost data are needed; monitoring alone does not remove risk.
Look for these in your work
- Both options considered
- Limit of prediction stated
- Recommendation evidence-based
Common mistakes
- Calling magnitude and intensity the same measure
- Treating every volcano type as explosive
- Assuming prediction can state an exact earthquake time
- Comparing impacts without comparing population exposure and vulnerability
What can you explain now?
What is the difference between an earthquake focus and epicentre?
Compare with the explanation
The focus is where rupture begins underground; the epicentre is the surface point above it
The two are related by location but are not the same place.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
How do magnitude, intensity and vulnerability differ when explaining a tectonic disaster?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.