Primary vs secondary impacts
Direct vs knock-on effects.
Primary impacts. Direct effects from the event. Immediate.
- Building collapse → casualties.
- Ground rupture, landslides.
- Lava flows, ash, pyroclastic flows.
Secondary impacts. Knock-on effects in hours/days/weeks.
- Tsunamis (if undersea earthquake).
- Fires from broken gas lines.
- Disease from contaminated water.
- Homelessness, displacement.
- Economic collapse.
Cambridge tip. Memorise the distinction. Most exam questions ask for SPECIFIC examples of each.
- Primary: shaking damage, lava flows.
- Secondary: tsunamis, fires, disease, displacement.
- Both matter; secondary often kills more long-term.
See the full worked example for impacts of earthquakes and volcanic eruptions →