Earthquake Waves - ESRT Page 11

Front

What are P-waves?

Back

P-waves, or primary waves, are the fastest seismic waves that travel through the Earth. They are compression waves that can move through solids, liquids, and gases.

Front

What are S-waves?

Back

S-waves, or secondary waves, are seismic waves that follow P-waves. They are shear waves that can only travel through solids and are slower than P-waves.

Front

How do you calculate the origin time of an earthquake?

Back

To calculate the origin time, subtract the travel time of the P-waves from the time they were recorded at the seismic station.

Front

What is the relationship between the distance to the epicenter and the arrival times of P-waves and S-waves?

Back

The greater the distance to the epicenter, the longer it takes for the P-waves and S-waves to arrive. The time difference between their arrivals can help determine the distance.

Front

What is the formula to calculate the distance traveled by P-waves?

Back

Distance = Speed x Time. P-waves travel at an average speed of about 6 km/s.

Front

What is the significance of the time difference between P-wave and S-wave arrivals?

Back

The time difference helps to determine the distance to the earthquake's epicenter. A larger time difference indicates a greater distance.

Front

If P-waves arrive at 02:54:40 pm and the epicenter is 2000 km away, how do you find the origin time?

Back

Calculate the travel time of P-waves to 2000 km, then subtract that time from 02:54:40 pm.

Front

What is the average speed of S-waves?

Back

S-waves travel at an average speed of about 3.5 km/s.

Front

How far do P-waves travel in 9 minutes and 30 seconds?

Back

P-waves travel approximately 5700 km in 9 minutes and 30 seconds (9.5 minutes).

Front

What is the time difference if P-waves arrive at 03:22:43 am and S-waves at 03:29:57 am?

Back

The time difference is 00:07:14.