P and S waves

Front

What is a seismograph?

Back

An instrument that detects and measures earthquakes.

Front

What are P waves?

Back

Primary waves that are the first to arrive at a seismic station during an earthquake.

Front

What are S waves?

Back

Secondary waves that arrive after P waves during an earthquake.

Front

How many seismic stations are needed to locate an earthquake's epicenter?

Back

Three seismic stations are necessary.

Front

What is the epicenter of an earthquake?

Back

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

Front

What is the focus of an earthquake?

Back

The point within the Earth where the earthquake originates.

Front

Which type of wave travels faster, P waves or S waves?

Back

P waves travel faster than S waves.

Front

What is the typical speed of P waves in the Earth's crust?

Back

P waves typically travel at speeds of 5 to 8 km/s.

Front

What is a seismogram?

Back

A record produced by a seismograph that shows the seismic waves of an earthquake.

Front

How long does it take for P waves to travel 2000 km?

Back

It takes approximately 4 minutes for P waves to travel 2000 km.