Front

What is the instrument used to measure earthquakes?

Back

Seismograph

Front

Where do most earthquakes in the United States happen?

Back

West Coast

Front

Which theory describes the motion of the force driving Earth's plates?

Back

Plate Tectonic theory

Front

Where does a quake begin on the surface?

Back

Epicenter

Front

What are the puzzle pieces of the Earth's surface called?

Back

Tectonic plates

Front

What is an earthquake?

Back

A sudden shaking of the ground caused by the movement of tectonic plates.

Front

What is the focus of an earthquake?

Back

The point inside the Earth where the earthquake originates.

Front

What is the difference between the epicenter and the focus of an earthquake?

Back

The epicenter is the point on the Earth's surface directly above the focus.

Front

What are aftershocks?

Back

Smaller earthquakes that occur after a larger earthquake.

Front

What is the Richter scale?

Back

A scale used to measure the magnitude of earthquakes.