New
New
Year 10
OCR
Higher

# Probing planet Earth

I can describe S waves and P waves produced by earthquakes and how they move through different parts of the Earth.

New
New
Year 10
OCR
Higher

# Probing planet Earth

I can describe S waves and P waves produced by earthquakes and how they move through different parts of the Earth.

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## Lesson details

### Key learning points

1. Earthquakes usually occur near to the edges of tectonic plates
2. P waves and S waves are produced deep underground where tectonic plates slip and cause vibrations in rock
3. P waves are longitudinal waves and travel through liquid
4. S waves are transverse waves and cannot travel through liquid layers inside Earth
5. P waves and S waves provide evidence for the internal structure of Earth

### Common misconception

Many students think the mantle is liquid or semi-liquid. Some think it contains soil or water.

The mantle is almost all solid rock. Less than 1% of it is liquid e.g. at spreading plate boundaries, subduction zones and hot-spots.

### Keywords

• Earthquake - An earthquake is caused by the sudden sliding movement of tectonic plates against each other.

• S wave - S waves are transverse seismic waves that travel through solids but not liquids.

• P wave - P waves are longitudinal seismic waves that travel at different speeds through solids and liquids.

• Transverse - A transverse wave is where the wave oscillates perpendicular to the direction of travel.

• Longitudinal - A longitudinal wave is where the wave oscillates along the direction of travel with areas of compression and rarefaction.

Use a role play with students standing shoulder to shoulder to show the way S and P waves move to explain that a solid (with students stuck together) transmits both but a liquid (where they can slide past each other) only transmits P waves.
Teacher tip

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Starter quiz

### 6 Questions

Q1.
What do waves transfer?
matter
water
Q2.
Fill in the gap: Water waves are an example of waves.
Correct Answer: transverse, transverse waves, a transverse wave
Q3.
What's the missing word? Sound waves and ultrasound are examples of waves.
transverse
electromagnetic
Q4.
Match the waves to their descriptions
Correct Answer:ultrasound,A wave that has too high a frequency to hear.

A wave that has too high a frequency to hear.

Correct Answer:microwaves,A wave used in mobile phone communications.

A wave used in mobile phone communications.

Correct Answer:light,A wave that we detect with our eyes.

A wave that we detect with our eyes.

Q5.
What happens when a wave is refracted?
Correct answer: The wave changes speed.
The wave always goes in the same direction.
The wave goes back to where it started.
Q6.
What type of waves cannot travel through liquids?
longitudinal and transverse waves
longitudinal waves only

## Exit quiz

### 6 Questions

Q1.
Where are tectonic plates found?
in the mantle
on the oceans' surface
between the mantle and the outer core
Q2.
Which statement best describes where earthquakes occur?
Correct answer: Near the edges of tectonic plates.
In the middle of continents.
Under the surface of oceans.
In mountainous regions of Earth.
Q3.
Which of the statements about S waves are correct?
Correct answer: The oscillations are perpendicular to the direction of travel.
Correct answer: They are transverse waves.
The oscillations are both perpendicular and parallel to the direction of travel.
They travel faster than P waves.
They can travel through liquids.
Q4.
Fill in the gap: P waves are seismic waves that travel at different speeds through solids and liquids.