Chapter 8 Homework

Major earthquakes are often followed by somewhat smaller events known as ________.

Aftershocks

P waves ________.

Are faster than S waves and surface waves

________ is the weak layer.

Asthenosphere

The position on Earth's surface directly above the earthquake source is called the ________.

Epicenter

Oceanic crust is less dense than continental crust.

False

Which of the following is determined by making direct observations in the area affected by an earthquake?

Intensity

________ is the rigid, cool outer approximately 100 km of the earth.

Lithosphere

Which one of the following statements is correct?

P and S waves travel through solids and P waves travel through liquids.

________ have the highest velocities?

Primary waves (P-waves)

One measurement that is widely used to determine how far the focus of an earthquake is from the seismograph where it is recorded is ________.

The difference in travel time between the P and the S wave

Strike-slip faults are common along ________ plate boundaries.

Transform

The Richter magnitude of an earthquake is determined from the ________.

amplitude of the largest seismic wave

Long term earthquake prediction is based on ________.

the assumption that large faults break in a cyclical manner

Which of the following is not a significant factor contributing to the damage caused by an earthquake?

the proximity to a plate boundary

A tsunami can occur ________.

when an earthquake occurs in the seafloor like along an oceanic plate boundary.