Earthquakes & Seismic Waves

Question 1

What is the focus in relation to an earthquake?

Answer 1

Point underground where earthquake starts

The focus is the initial point of rupture in the Earth’s crust that generates seismic waves.

Question 2

What is the epicenter of an earthquake?

Answer 2

Point on surface above focus

The epicenter is directly above the focus and is the location on the Earth’s surface where the earthquake is felt most strongly.

Question 3

Which type of seismic wave is the fastest?

Answer 3

P-Waves

P-Waves can travel through both solids and liquids, making them the fastest seismic waves.

Question 4

What are S-Waves and how do they differ from P-Waves?

Answer 4

Slower, only through solids

S-Waves cannot travel through liquids, which limits their propagation compared to P-Waves.

Question 5

What do seismic waves reveal about the Earth?

Answer 5

Earth’s interior structure

By analyzing seismic waves, scientists can infer the composition and state of different layers within the Earth.

Question 6

Where do earthquakes commonly occur?

Answer 6

Often at plate boundaries

The movement of tectonic plates at their boundaries is a primary cause of earthquakes.

Question 7

What does magnitude measure in an earthquake?

Answer 7

Energy released (Richter Scale)

The Richter Scale quantifies the amount of energy released during an earthquake.

Question 8

What does intensity measure in the context of earthquakes?

Answer 8

Damage caused (Mercalli Scale)

The Mercalli Scale assesses the impact of an earthquake based on observed effects and damage.

Question 9

What are shadow zones?

Answer 9

Areas where waves don’t reach; show liquid outer core

Shadow zones indicate regions of the Earth that are not reached by seismic waves, providing evidence of the liquid outer core.