Earthquake Basics

What is the primary movement direction in a strike-slip fault?

• Vertical

• Horizontal

• Diagonal

• Circular

What does each whole number increase on the Richter scale represent?

• A doubling of the earthquake's duration

• A tenfold increase in the amplitude of the seismic waves

• A decrease in the earthquake's intensity

• A fivefold increase in the earthquake's speed

Tags

NGSS.HS-PS4-1

What do Primary (P) waves do to rocks?

• Shake them perpendicular to wave travel

• Compress and expand them in the direction of wave propagation

• Move them along the Earth's surface

• Cause them to melt

Tags

NGSS.MS-PS3-5

What is the main characteristic of Secondary (S) waves?

• Fastest waves

• Waves that compress rocks

• Slower waves that shake the ground perpendicular to travel

• Waves that travel through water

Tags

NGSS.MS-PS4-2

Where does an earthquake begin?

• Epicenter

• Fault

• Focus

• Joint

This is the area beneath the Earth's surface where the earthquake begins

• epicenter

• focus

• fault line

• tectonic plate

Answer explanation

The area beneath the Earth's surface where an earthquake begins is referred to as the 'focus'. This is not the 'epicenter', which is the point on the surface above the focus. It's also not the 'fault line' or the 'tectonic plate', which are larger geological structures. So, the correct answer to the question is 'focus'.

Tags

NGSS.MS-ESS3-2

What is a seismograph used for?

• To measure temperature

• To record and measure the motion of the ground during an earthquake

• To predict weather patterns

• To calculate wind speed

Tags

NGSS.MS-ESS3-2

During an earthquake, what remains stationary in a seismograph?

• The entire device

• The recording paper

• The suspended weight or mass

• The outer casing

Which scale is used to measure the magnitude of an earthquake?

• Beaufort scale

• Richter scale

• Fujita scale

• Saffir-Simpson scale

What does the Moment Magnitude Scale measure?

• The speed of the earthquake

• The length of the earthquake in time

• The size of the earthquake in magnitude

• The direction of an earthquake