Chapter 19: Earthquakes

Movement occurs along fractures in rocks when _____.

• stress equals the strength of the rocks involved

• stress overcomes the strength of the rocks involved

• stress is applied to the rocks involved

• stress is less than the strength of the rocks involved

The strain which causes a material to twist is known as _____.

• stress

• compression

• tension

• shear

The strain which causes a material to pull apart is known as _____.

• stress

• compression

• tension

• shear

P-waves and S-waves are also known as _____.

• surface waves

• ground waves

• body waves

• first waves

Which point marks the epicenter of the earthquake?

• A

• B

• C

• D

At which point will the most damage as a result of the earthquake occur?

• A

• B

• C

• D

What is true about the focus?

• it is the point where the most surface damage will occur

• it is the point where the surface waves originate and spread out

• it is the point where the waves are attracted

• it is the point of failure where the waves originate

A seismogram is located 4500 miles away from the epicenter of an earthquake. What is the difference in time between when the P-waves reach the seismogram and the S-waves reach the seismogram?

• 5 1/2 minutes

• 6 minutes

• 10 minutes

• 22 minutes

P-waves reach a seismogram 6 minutes after an earthquake occurs and the S-waves arrive 3 and a half minutes later. How far is the seismogram from the epicenter of the earthquake?

• 1000 km

• 2000 km

• 3000 km

• 4000 km

Seismologists have assessed a particular area and predicted that an earthquake occurs every 17 years in that area. If the last earthquake occurred in 2018, when will the next earthquake most likely occur?

• 2030

• 2035

• 2040

• 2025