35.5.1. Earthquake Magnitude

Try these first

1. 1.

   What does PGA stand for?

   Hint

   Think of what it measures in terms of ground movement.

2. 2.

   Does a higher earthquake magnitude always mean a higher PGA?

   Hint

   Consider how the increase rate changes.

3. 3.

   What is Peak Ground Acceleration primarily used for?

   • To measure temperature
   • To inform seismic design
   • To assess wind speed

   Hint

   Consider what happens during an earthquake.

4. 4.

   True or False: The increase in PGA continues to be proportional with increasing earthquake magnitude indefinitely.

   • True
   • False

   Hint

   Think about how energy behaves as it grows.

5. 5.

   Suppose an earthquake of magnitude 7.2 reports a PGA of 0.45g at a nearby location. What might happen to the PGA if the magnitude increases to 8.2, considering attenuation effects?

   Hint

   In nonlinear relationships, expect slow growth after a certain point.

6. 6.

   Discuss how engineers utilize seismic code factors to determine safety measures for buildings located on soft soil in a region prone to high-magnitude earthquakes.

   Hint

   Think critically about inputs to design codes and regional challenges faced.