Journey to the Centre of the Earth

The three parts to this program are three separate but linked activities, and all are related to seismic waves and the information that they provide about the structure of the Earth.

• Part 1 "Investigating seismic waves" introduces you to the different types of seismic waves and their properties.
• In Part 2 "Travel time graphs" you will measure the P-wave speed in the upper layer of the Earth, and will determine how deep this layer extends.
• In Part 3 "Down to the centre" you will use travel time graphs to investigate two topics: the type of rock that makes up the Earth's mantle, and the structure of the Earth's core.

We advise you to start by reading as far as the beginning of Section 6.2.1 of Chapter 6 in Book 2 before doing Activity 6.1, which involves studying Part 1 of the 'journey'. You will then need to study more of Chapter 6 before tackling the second part of the 'journey' (Activity 6.2), and then more again before the third part of the 'journey' (Activity 6.3).

Estimated study time: 1¾ hours (30, 45 and 30 minutes for the three parts respectively) but with a further hour or more to study the sections of Book 2 that come between the Activities.