20.14. Depth of Focus

Try these first

1. 1.

   What is the depth range for shallow focus earthquakes?

   Hint

   Think of the shallowest part of the ocean.

2. 2.

   Which type of earthquake is generally less destructive?

   Hint

   They happen far below the surface.

3. 3.

   What depth classifies an earthquake as shallow focus?

   • < 70 km
   • 70-300 km
   • > 300 km

   Hint

   This is the closest range to the Earth's surface.

4. 4.

   True or False: Deep focus earthquakes cause the most surface shaking.

   • True
   • False

   Hint

   Think about the depth and energy distribution.

5. 5.

   Analyze and compare the potential risks associated with building a structure in a region prone to shallow focus earthquakes versus one in a deep focus earthquake region.

   Hint

   Consider building materials and designs tailored to the threat level.

6. 6.

   Using the depth categories (shallow, intermediate, deep), develop a risk assessment strategy for a community that must decide where to build emergency shelters.

   Hint

   Think about how different depths influence shaking intensity.