Design for the AQA GCSE 9-1 specification this lesson follows the waves part of the course. Students will build upon their knowledge of transverse and longitudinal waves and at the end of the lesson students should be able to:

- Label the structure of the Earth and identify P, S and L waves on a seismometer trace.
- Complete the table recalling the properties of P and S waves.
- Describe and explain how evidence suggests that the Earth contains a liquid outer core.