Good Learning Co.
SavannahYear 8
← Geography
GeographyGCSE natural hazards30 min★★★ difficulty

Tectonic hazards: plates, margins and why depth matters

Earthquakes and volcanoes are not scattered at random. Learn the margins properly in week one and every case study afterwards becomes easier to explain.

Lesson overview

What you'll learn in this lesson

Explain tectonic and weather hazards, their effects and the management of risk in contrasting places.

Key learning points

  • • Plate movement and the three margins
  • • Primary and secondary effects
  • • Why the same magnitude kills differently
  • • Managing risk

This lesson at a glance

  • 30 minutes
  • 17 parts to scroll through
  • 4 quick checks
  • Marked quiz at the end
  • Gentle pace: short sittings with pauses

Words to know

tectonicweatherhazardseffectsmanagement

Scroll down — the lesson carries on below

Part 1 of 17 · Discover6%
1

Watch & discover

Part 1 of 17

Watch first

Tectonic hazards: plates, margins and why depth matters

An English teaching video on this topic from Miss Mooney Geography. Watch it, then scroll down for the lesson.

In a nutshell

Explain tectonic and weather hazards, their effects and the management of risk in contrasting places.

2

Learning cycle

Part 2 of 17

Learning cycle 1 of 2

Part 1 · Plate movement and the three margins

A short piece of teaching, then a check to make sure it has landed.

3

Explore the idea

Part 3 of 17

Learn

Plate movement and the three margins

Convection and slab pull drag the plates across the asthenosphere. At a destructive margin oceanic crust subducts beneath continental crust, generating deep earthquakes and explosive composite volcanoes. At a constructive margin plates separate, magma rises and shield volcanoes with runny basaltic lava form. At a conservative margin plates slide past one another; friction locks them, stress builds and releases as an earthquake — no volcano, because no magma reaches the surface.

4

Explore the idea

Part 4 of 17

Learn

Primary and secondary effects

Primary effects happen at the moment of the event: buildings collapse, people are killed, roads fracture. Secondary effects follow from those: fire from ruptured gas mains, disease from broken water pipes, homelessness, lost income, tsunami. Exam answers lose marks by mixing the two, so label them explicitly.

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Quick check

Part 5 of 17

Quick check

Which margin produces explosive composite volcanoes?

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Quick check

Part 6 of 17

Quick check

Which is a secondary effect of an earthquake?

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Learning cycle

Part 7 of 17

Learning cycle 2 of 2

Part 2 · Why the same magnitude kills differently

A short piece of teaching, then a check to make sure it has landed.

8

Reset break

Part 8 of 17

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
9

Explore the idea

Part 9 of 17

Learn

Why the same magnitude kills differently

A magnitude 7 event in a high-income country and in a low-income country produce very different death tolls. Building codes, emergency planning, hospital capacity, road access and the money to enforce regulation all change the outcome. Wealth is the underlying variable behind almost every contrast you will be asked to explain.

10

Explore the idea

Part 10 of 17

Learn

Managing risk

Four strategies recur: monitoring, prediction, protection and planning. Volcanoes can be monitored and, to a degree, predicted; earthquakes cannot be predicted reliably, so protection (aseismic design) and planning (drills, exclusion zones, insurance) carry more weight.

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Quick check

Part 11 of 17

Quick check

Why is no volcano found at a conservative margin?

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Quick check

Part 12 of 17

Quick check

Which management strategy is least reliable for earthquakes?

13

Explore the idea

Part 13 of 17

Worked example

Model answer: 'Explain why effects differ between two contrasting areas of similar magnitude' (6 marks)

The magnitude of an event sets the energy released, but the effects depend on the vulnerability of the place. In a higher-income country, seismic building regulations mean frames flex rather than collapse, so primary effects such as deaths from building failure are reduced; well-funded emergency services also limit secondary effects, because fires are contained and water supplies restored quickly. In a lower-income country, informal housing built without reinforcement collapses under the same shaking, and limited hospital and road capacity means injuries become deaths and disease spreads through damaged sanitation. The difference in effects is therefore chiefly a difference in wealth and governance rather than in the hazard itself.

14

Challenge round

Part 14 of 17

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

15

Challenge round

Part 15 of 17

Game · Fill the gaps

Finish the sentences

Choose the word that belongs in each gap.

Primary ____ happen at the moment of the event: buildings collapse, people are killed, roads fracture.

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Mastery quiz

Part 16 of 17

Marked quiz

End of lesson quiz: Tectonic hazards: plates, margins and why depth matters

4 questions, marked with the reasoning shown. No timer.

  1. 1. Which margin produces explosive composite volcanoes?

  2. 2. Which is a secondary effect of an earthquake?

  3. 3. Why is no volcano found at a conservative margin?

  4. 4. Which management strategy is least reliable for earthquakes?

17

Lesson round-up

Part 17 of 17

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

0

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Flooding on the River Calder

The town of Harbrook sits where a steep valley opens onto a flat floodplain. In December 2015, 120 mm of rain fell in 36 hours onto ground that was already saturated. The river rose 2.4 m in five hours, and 380 homes and 54 businesses flooded. Two roads and the railway closed for eleven days.

Geographers pointed to physical causes — steep slopes, impermeable rock, heavy rainfall — and human causes: moorland drained upstream, new housing built on the floodplain, and drains designed for smaller storms.

Since then the town has planted 40 hectares of woodland upstream, built leaky dams in small streams, and raised flood walls to 1.8 m. In the storm of 2020 the peak river level was 0.3 m lower and 40 homes flooded, not 380.

Written for Good Learning Co.

Reading questions

  1. List two physical and two human causes of the 2015 flood.
  2. Explain how planting woodland upstream lowers the river's peak level.
  3. Using the figures, judge how successful the scheme has been. Quote data in your answer.

  • Case study notes

    Writing

    Write the place, the facts and the figures from this lesson so you can revise them later.

    Half a page

  • Explain answer

    Writing

    Answer in full sentences, giving causes and effects. Use one figure or place name as evidence.

    8–10 sentences

  • Map or sketch

    Diagram

    Draw the map, cross-section or field sketch with a key, title and labels, then photograph it.

    1 map with a key

  • Data work

    Working out

    Plot your figures as a graph on paper and write one sentence about the pattern.

    1 graph + 1 sentence

Saved as you type.

Part 1 of 17 · Watch & discover

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