Earthquakes release energy as seismic waves. P waves travel faster and through solids and liquids; S waves travel more slowly and only through solids. Comparing wave arrival times at several stations helps estimate distance and locate an earthquake epicentre.
Example
A larger gap between P-wave and S-wave arrival times indicates that a recording station is farther from the earthquake.
Key terms
Seismic wave:
Energy that travels through Earth after an earthquake.
Epicentre:
The point on Earth's surface directly above an earthquake focus.
Seismograph:
An instrument that detects and records ground motion.
Questions
1. Which statement best captures earthquake waves and locating epicentres?
Differences in seismic-wave behaviour provide evidence about earthquake location and Earth's interior.
The first seismic wave recorded is always the most damaging wave.
The pattern can only be explained by guessing.
The topic has no observable evidence.
2. Which term means "Energy that travels through Earth after an earthquake."?
Seismic wave
Epicentre
Seismograph
Variable
3. Which term means "The point on Earth's surface directly above an earthquake focus."?
Epicentre
Seismic wave
Seismograph
Conclusion
4. Which term means "An instrument that detects and records ground motion."?
Seismograph
Seismic wave
Epicentre
Prediction
5. Which observation task is most relevant to this topic?
Compare three simplified seismograms and record the P-S arrival-time gap for each.
Copy the topic title without looking at an example.
Choose a result before making observations.
Ignore details that do not match a first guess.
6. Which model would best represent the key process or relationship?
Draw wave paths from an earthquake focus to several recording stations.
A decorative drawing with no labels or connection to evidence.
A list of unrelated facts.
A model that deliberately contradicts every observation.
7. Which investigation is focused most directly on the scientific idea?
Use three station-distance circles on a map to triangulate a model epicentre.
Change many uncontrolled factors and record nothing.
Ask only for opinions and treat them as measurements.
Repeat a memorised answer without testing it.
8. Which evidence best supports the lesson explanation?
Three distance estimates narrow the location to the common intersection more reliably than one station alone.
The first seismic wave recorded is always the most damaging wave.
One preferred answer with no observation.
A claim that cannot be checked in any way.
9. Which task applies the science in a new context?
Explain how seismic monitoring supports emergency planning even though exact earthquakes cannot be predicted.
Write the heading again without explaining it.
Ignore the system and choose randomly.
Assume the same answer fits every situation.
10. Which response best corrects the misconception in this topic?
Differences in seismic-wave behaviour provide evidence about earthquake location and Earth's interior.
The first seismic wave recorded is always the most damaging wave.
Both statements must be equally correct.
Evidence cannot help decide between explanations.
11. What makes a scientific observation useful?
It records relevant details without changing them to fit an expectation.
It includes only details that support a preferred answer.
It replaces measurements with guesses.
It hides the conditions under which it was made.
12. Why should a scientific model include its limitations?
Models simplify reality, so users need to know what the representation leaves out.
A limitation proves the model has no value.
Models are exact copies and never omit anything.
Limitations should be hidden so a model looks certain.
13. What makes a comparative investigation fair?
Change or compare the intended factor while keeping other relevant conditions consistent.
Change every condition at the same time.
Measure only the result that looks best.
Decide the conclusion before collecting data.
14. Why repeat measurements or use several samples?
To reveal variation and reduce the influence of chance or one unusual result.
To guarantee a preferred conclusion.
To make units unnecessary.
To remove the need for a clear method.
15. What is the best response to an anomalous result?
Record it, check the method and investigate whether it is error or meaningful variation.
Delete it automatically.
Delete all other results instead.
Assume it proves the whole topic wrong.
16. Which conclusion is scientifically responsible?
One that answers the question, uses the evidence and states important limits.
One that claims more than the data show.
One that ignores conflicting evidence.
One based only on the expected answer.
17. What would make the claim about earthquake waves and locating epicentres stronger?
Several relevant, repeatable evidence lines that agree with the explanation.
A larger heading and no new evidence.
Removing results that are inconvenient.
Relying on a single uncheckable opinion.
18. What should happen if reliable new evidence conflicts with a model?
The model should be reviewed and revised or replaced if needed.
The evidence should always be hidden.
The original model must never change.
Scientists should stop asking questions.
19. How should safety and ethics shape an investigation?
Risks, people, living things and environments should be considered before the method is used.
Safety matters only after data collection.
Any method is acceptable if it is fast.
Ethics has no place in science.
20. What makes science communication trustworthy?
Clear methods, accurate terms, relevant evidence and acknowledgement of uncertainty.
Certainty without evidence.
Leaving out how results were obtained.
Using dramatic language instead of data.
21. What is the strongest overall outcome from studying earthquake waves and locating epicentres?
Use observations, models, investigations and evidence to explain and apply this idea.
Memorise the title without using it.
Avoid testing explanations.
Treat every first idea as permanently correct.
Answer key (parent copy)
1. Differences in seismic-wave behaviour provide evidence about earthquake location and Earth's interior.
2. Seismic wave
3. Epicentre
4. Seismograph
5. Compare three simplified seismograms and record the P-S arrival-time gap for each.
6. Draw wave paths from an earthquake focus to several recording stations.
7. Use three station-distance circles on a map to triangulate a model epicentre.
8. Three distance estimates narrow the location to the common intersection more reliably than one station alone.
9. Explain how seismic monitoring supports emergency planning even though exact earthquakes cannot be predicted.
10. Differences in seismic-wave behaviour provide evidence about earthquake location and Earth's interior.
11. It records relevant details without changing them to fit an expectation.
12. Models simplify reality, so users need to know what the representation leaves out.
13. Change or compare the intended factor while keeping other relevant conditions consistent.
14. To reveal variation and reduce the influence of chance or one unusual result.
15. Record it, check the method and investigate whether it is error or meaningful variation.
16. One that answers the question, uses the evidence and states important limits.
17. Several relevant, repeatable evidence lines that agree with the explanation.
18. The model should be reviewed and revised or replaced if needed.
19. Risks, people, living things and environments should be considered before the method is used.
20. Clear methods, accurate terms, relevant evidence and acknowledgement of uncertainty.
21. Use observations, models, investigations and evidence to explain and apply this idea.