35.7. Empirical Relationships and Attenuation Models

Try these first

1. 1.

   What does PGA stand for?

   Hint

   Think about measuring ground motion during an earthquake.

2. 2.

   What is the primary purpose of GMPEs?

   Hint

   Consider why we need predictions in seismic design.

3. 3.

   What is the value of M in the GMPE formula?

   • Magnitude of the earthquake
   • Distance from the epicenter
   • Depth of the earthquake

   Hint

   What do we measure on the Richter scale?

4. 4.

   True or False: The constants in GMPEs are always the same for every earthquake model.

   • True
   • False

   Hint

   Consider why different regions might need different constants.

5. 5.

   Using the following GMPE coefficients: a=0.1, b=0.3, c=0.7, d=1.0, calculate the PGA for a magnitude 7.0 earthquake located 20 km from the site. Consider the importance of site conditions in adjusting your answer.

   Hint

   Apply the base logarithmic equation stepwise.

6. 6.

   Given two GMPEs, one for subduction zones and another for intraplate regions, compare and discuss how PGA predictions might differ based on tectonic settings. Use examples from real earthquakes.

   Hint

   Look into the features of past earthquakes in both regions.