Lesson Y8-U01-L06

Y8-U01-L06 Measuring Earthquakes: The Moment Magnitude Scale Quiz: KS3 Geography, Unit 7

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson Y8-U01-L06, Measuring Earthquakes: The Moment Magnitude Scale: 20 multiple choice questions for the KS3 Geography (National Curriculum), Unit 7: Year 8: Restless Earth: Tectonic Hazards, written with Revision Ninja.

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The 20 questions

  1. What is a seismometer?

    • A map showing the depth of the ocean floor and the position of the sea trenches
    • A scale that weighs rock samples from a volcano
    • An instrument that detects and records the shaking of the ground
    • A tool that measures rainfall in millimetres each day

  2. What is a seismograph?

    • A device for measuring air pressure at height
    • A map showing where earthquakes have happened, with the dates of each quake
    • The wiggly line a seismometer draws to record shaking
    • A chart of rainfall for each month of the year

  3. What does the heavy weight inside a seismometer do?

    • It stays still while the ground moves, so the movement can be recorded
    • It heats the instrument to keep it working in cold conditions during the winter months
    • It pushes the ground down to make it stable
    • It sends a signal to warn people of the quake

  4. What does a taller wiggle on a seismograph show?

    • A longer period of calm before the quake
    • A stronger, more violent movement of the ground
    • An earthquake that happened under the sea
    • A deeper focus, far below the surface, where the rocks are much more solid

  5. What is the moment magnitude scale?

    • The scale that replaced the Richter scale for measuring large earthquakes
    • A map scale used to show distances on Ordnance Survey maps
    • A scale that measures wind speed in storms and the height of waves at sea
    • A scale for measuring the depth of soil layers

  6. What does it mean that the magnitude scale is logarithmic?

    • The scale only goes up to 5 before it starts again
    • Each whole step up means about ten times more shaking, not one more
    • Each whole step means exactly one more unit of energy
    • The scale is counted in steps of half a unit each, so each step adds a little more shaking

  7. About how many times more energy is released for each whole step of magnitude?

    • About 32 times
    • About 2 times
    • About 10 times
    • About 100 times

  8. Why do scientists use several recording stations for one earthquake?

    • To make the earthquake look bigger on the map so that it is easier for people to see
    • Because each station records a different earthquake
    • Because one station cannot record shaking at all
    • To check the results and make the measurements more reliable

  9. How many times more shaking is a magnitude 8 earthquake than a magnitude 6 earthquake?

    • About 1,000 times more
    • About 100 times more
    • About 2 times more
    • About 20 times more

  10. How much more shaking does a magnitude 5 earthquake produce than a magnitude 4?

    • About 32 times more
    • About 2 times more
    • About 100 times more
    • About 10 times more

  11. Which pair of earthquakes would differ by about 1,000 times in shaking?

    • Magnitude 5 and magnitude 6
    • Magnitude 4 and magnitude 7
    • Magnitude 6 and magnitude 6.5
    • Magnitude 4 and magnitude 5

  12. A distant seismograph station is compared with a nearby one for the same earthquake. What would its record show?

    • Identical wiggles, because distance does not affect shaking
    • Smaller wiggles, because shaking weakens with distance from the focus
    • Taller wiggles, because distant stations pick up stronger waves
    • No wiggles at all, because waves cannot travel far through the ground and so the station stays quiet

  13. A pupil says magnitude 6 is twice as strong as magnitude 3. Which response is best?

    • No, the scale is logarithmic, so three whole steps mean about 1,000 times more shaking
    • Yes, because each step means exactly two times more shaking
    • Yes, because magnitudes are measured along a straight line, so each step adds the same amount of shaking
    • No, magnitude 3 is stronger, because lower numbers mean more energy

  14. Which statement about a seismometer is correct?

    • It moves with the ground, so it records no shaking at all
    • It keeps a heavy weight still so that the moving ground can be measured
    • It measures wind speed through the ground
    • It is used only on the ocean floor, where it records shaking from the waves of the sea

  15. A quake is recorded as magnitude 6. Why would geographers still check readings from other stations?

    • Because stations must all share the same heavy weight
    • To confirm the magnitude with several independent recordings
    • Because one station always gives a wrong reading, so the others are needed to correct it
    • Because magnitude changes depending on the weather

  16. Which magnitude shakes the ground about 10 times more than magnitude 3?

    • Magnitude 3.5
    • Magnitude 5
    • Magnitude 6
    • Magnitude 4

  17. Why is a logarithmic scale useful for measuring earthquakes?

    • It makes all earthquakes look equally strong on a map
    • It removes the need for seismometers at all stations, because the scale can be read from a map
    • It stops scientists from comparing different earthquakes
    • Earthquakes vary enormously in energy, so a compact scale can show both small and huge quakes

  18. Two stations record similar wiggle heights for the same quake. What can be concluded?

    • The two stations must have recorded different earthquakes
    • The stations must be faulty and should be discarded
    • The earthquake must have happened under the ocean, which is why the two readings agree closely
    • The two readings are consistent, so the magnitude estimate is more reliable

  19. Which statement best explains why a magnitude 8 earthquake is far more dangerous than a magnitude 6?

    • It is always closer to cities, so it shakes them more
    • It is measured by a different instrument that exaggerates the number
    • It only shakes the ground for a shorter time, so people have more time to escape from their homes
    • It releases far more energy, giving much stronger shaking over a much wider area

  20. Why should a pupil avoid describing the magnitude scale as a simple counting scale?

    • It counts the number of people killed by the quake
    • Magnitude is measured in degrees, like temperature, using a thermometer placed in the ground
    • Each step means about ten times more shaking, so the numbers grow very quickly
    • The scale runs backwards, with bigger numbers meaning weaker quakes

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