Characteristics, Distribution, and Measurement of Earthquakes

Question 1

What are the three main scales used to measure earthquakes?

Answer 1

Richter Scale: Measures the magnitude based on seismic wave amplitude.

Moment Magnitude Scale (Mw): Measures the total energy released.

Mercalli Intensity Scale: Measures the effects and damage caused by the earthquake.

Question 2

Where are earthquakes most commonly distributed and why?

Answer 2

Along fault lines and plate boundaries, especially at convergent and transform boundaries, due to tectonic movements.

Question 3

Define the focus and epicenter of an earthquake.

Answer 3

Focus: The point within the Earth where the earthquake originates.

Epicenter: The point directly above the focus on the Earth’s surface.

Question 4

What are the three main types of seismic waves?

Answer 4

P-waves (Primary waves): Compressional waves that travel fastest.

S-waves (Secondary waves): Shear waves that are slower and cannot travel through liquids.

Surface Waves: Travel along the Earth’s surface, causing most of the damage.