Ch. 3 Earthquakes & Volcanoes

A break in Earth's lithosphere where one block of rock moves toward, away from, or past another..

• Tsunami

• Fault

• Focus

• Surface Waves

What is a graphical illustration of seismic waves?

• Seismogram

• Mercalli scale

• Richter scale

• Secondary Waves

The point beneath Earth’s surface where rock breaks under stress and triggers an earthquake is called the

• vent.

• shield.

• epicenter.

• focus.

The type of seismic waves that arrive first and move by compressing and expanding the ground like an accordion are called

• S waves.

• P waves.

• Surface waves.

• Mercalli waves.

S waves are also known as

• primary waves.

• secondary waves.

• surface waves.

• focus waves

If the Coast Guard warns of a giant wave of water approaching the shore as a result of a major earthquake, they are warning of

• an aftershock.

• liquefaction

• a tsunami.

• landslides

The risk of earthquakes is high along the Pacific coast of the United States because

• there have been no earthquakes there lately.

• that’s where the Pacific and North American plates meet. 

• satellites have detected increasing elevation of the ground surface.

• serious earthquakes are rare east of the Rockies.

The rating system that estimates the total energy released by an earthquake is called the

• Richter scale.

• moment magnitude scale.

• mechanical seismograph scale.

• Mercalli scale.

The formation of the Hawaiian Islands is one example of

• volcanoes forming over a hot spot.

• volcanoes forming along plate boundaries.

• the Ring of Fire.

• continental drift.

Before lava reaches the surface, the molten material is called

• rock.

• magma.

• volcanic ash.

• liquid fire.