Seismic Waves

Question 1

What are seismic waves?

Answer 1

Seismic waves are produced by earthquakes and volcanic eruptions.

Question 2

What have scientists used to determine the internal structure of the Earth?

Answer 2

Scientists have used the properties of seismic waves.

Question 3

What are seismic waves?

Answer 3

Waves produced by an earthquake or volcanic eruption that travel through the Earth

Seismic waves can be detected by instruments called seismometers.

Question 4

What instruments detect seismic waves?

Answer 4

Seismometers

These instruments measure the seismic waves generated by earthquakes or volcanic eruptions.

Question 5

What can scientists learn from seismic waves?

Answer 5

The inner structure of the Earth

By measuring the time it takes for seismic waves to reach different points and identifying locations they don’t reach.

Question 6

What do scientists measure to study seismic waves?

Answer 6

• The time it takes for the seismic waves to reach different points on the surface
• Which places the seismic waves don’t reach

This information helps infer the Earth’s internal structure.

Question 7

What happens if seismic waves do not reach a location?

Answer 7

They must have been reflected or refracted by a boundary between different types of material

This indicates a change in material properties within the Earth.

Question 8

What are the two types of seismic waves?

Answer 8

• P waves
• S waves

These waves have different characteristics and behaviors as they travel through the Earth.

Question 9

What are P waves?

Answer 9

Longitudinal waves that travel at different speeds through solids and liquids

P waves are the fastest seismic waves.

Question 10

What are S waves?

Answer 10

Transverse waves that cannot travel through liquids

S waves are slower than P waves and only travel through solid materials.