seismic waves

Question 1

What natural event causes seismic waves to be produced? What types are produced?

Answer 1

Earthquakes. They produce surface waves, P-waves and S-waves.

Question 2

State a difference between the mediums that P-waves and S-waves can travel through.

Answer 2

P-waves travel through both solids and liquids. S-waves only travel through solids (not liquids).

Question 3

Are P-waves transverse or longitudinal?

Answer 3

Longitudinal.

Question 4

Are S-waves transverse or longitudinal?

Answer 4

Transverse.

Question 5

Are surface waves transverse or longitudinal?

Answer 5

Longitudinal.

Question 6

Are S-waves faster or slower than P-waves?

Answer 6

Slower.

Question 7

Explain briefly how seismometer stations determine the location of earthquake epicentres.

Answer 7

The station detects the seismic P and S waves and measures the time differential, which is used to calculate the distance they have travelled.

Question 8

Why are multiple seismometer stations required to determine the epicentre’s exact location?

Answer 8

The detectors can only give a distance from the station not a direction. Distances from at least 3 different stations are required to pinpoint the exact position.

Question 9

What happens to the speed of seismic waves as they travel towards the Earth’s mantle?

Answer 9

Their speed increases.

Question 10

What is the S wave shadow zone and what does it show?

Answer 10

The area on the Earth’s surface that S waves can’t reach during an earthquake. This led to the model of the Earth having a liquid part of its core.

Question 11

What are the 4 main layers composing the Earth?

Answer 11

1. Crust 2. Mantle 3. Outer Core (liquid) 4. Inner Core (solid)