Earthquakes occur where solid rocks move against other solid rocks. Energy released during earthquakes is generated when rocks break. Locations of earthquakes, therefore, provide information on where Earth's crust breaks in response to pressure.

  !   Click the buttons below to show the locations and depths of selected earthquakes that occurred between 1968 and 1999.

What can you infer about Earth's crust where shallow, intermediate, and deep earthquakes occur?

2. How deep are the deepest earthquakes?

3. What does the lack of earthquakes below the depth you reported in question 2 suggest about the rocks at that depth?