Earthquakes and Seismic Waves

An earthquake is...

• the sudden release of energy in the Earth’s crust that creates a loud noise.

• a phenomenon that occurs when volcanic eruptions happen underwater.

• the shaking and trembling that results from movement of rock beneath Earth’s surface.

• the gradual movement of tectonic plates that leads to the formation of mountains.

Answer explanation

An earthquake is the shaking and trembling that results from movement of rock beneath Earth’s surface.

Tags

NGSS.MS-ESS3-2

Most earthquakes are...

• destructive.

• too small to notice.

• really big.

• caused by volcanic eruptions.

Answer explanation

Most earthquakes are too small to notice. But a large earthquake can crack open the ground, shift mountains, and cause great damage.

Tags

NGSS.MS-ESS3-2

___________ waves are vibrations that are similar to sound waves.

• Seismic

• Ocean

• Transverse

• Standing

Answer explanation

Seismic waves are vibrations that are similar to sound waves. They travel through Earth carrying energy released by an earthquake.

Tags

NGSS.MS-PS4-1

The _______ is the area beneath Earth’s surface where rock that was under stress begins to break or move.

• crust

• red zone

• hot spot

• focus

Answer explanation

The focus is the area beneath Earth’s surface where rock that was under stress begins to break or move. This action triggers an earthquake.

What is the point on the Earth's surface directly above the focus of an earthquake called?

• Epicenter

• Hypocenter

• Fault line

• Seismic zone

Answer explanation

The point on the surface directly above the focus is called the epicenter.

Tags

DOK Level 2: Skill/Concept

Which of the following is NOT a type of seismic wave?

• P Waves

• S Waves

• Transitional Waves

• Surface Waves

Answer explanation

An earthquake sends out only P and S waves from its focus. Surface waves can develop wherever P and S waves reach the surface.

P waves can travel through...

• neither solids nor liquids

• only solids

• both solids and liquids

• only liquids

Answer explanation

P waves travel through both solids and liquids, S waves cannot move through liquids.

The amount of earthquake damage or shaking that is felt is rated using which scale?

• The Seismic scale

• The Moment Magnitude scale

• The Richter scale

• The Modified Mercalli scale

Answer explanation

The Modified Mercalli Scale rates the amount of shaking from an earthquake. The shaking is rated by people’s observations, without the use of any instruments.

What is a seismograph?

• A machine that generates electricity from seismic energy.

• A device that monitors weather patterns and storm activity.

• A tool used to predict volcanic eruptions based on gas emissions.

• An instrument that records and measures an earthquake’s seismic waves.

Answer explanation

A seismograph is an instrument that records and measures an earthquake’s seismic waves.

Where is the Modified Mercalli scale used the most?

• In regions where there are many mountains, rivers, and valleys.

• In regions where there aren’t many instruments to measure an earthquake’s strength.

• In regions where there are many instruments to measure an earthquake’s strength.

• In regions that are highly populated and crowded with buildings.

Answer explanation

The Modified Mercalli scale is useful in regions where there aren’t many instruments to measure an earthquake’s strength. This is because the shaking is rated by people’s observations, so there is no need for scientific instruments.