Practice Question

1.State the name of the two types of Seismic Waves.

P waves and S waves

2. State 3 characteristics of P waves

P waves faster than S waves

P waves are longitudinal waves

P waves are known as primary waves

P waves can travel through solids and liquids

3. State 3 characteristics of S waves

S waves are secondary waves

S waves are slower than P waves

S waves can only travel through solids, not liquids

S waves are transverse waves

4. What is the role of a seisometer?

Detects seismic waves such as P waves and S waves

5. During an earthquake would a person within the area experience a P wave or S wave first

P waves

6. Describe the evidence for the outer core being liquid

Evidence that there the outer core is liquid is provided by P waves being refracted (change direction) at the boundary between the mantle and the outer core, this direction change happens twice, once when entering and once when leaving the outer core. This leads to the formation of a P-wave shadow zone. 

The other evidence for outer core being liquid is that S waves will NOT travel through the outer core, this creates a large S wave shadow zone. 

7. Describe the evidence that the inner core is solid

Evidence that the inner core is a solid, is provided by the existence of VERY weak P waves within the P wave shadow zone. These are caused by the solid inner core refracting P waves into the Shadow zone.