28.10.1. Introduction to Attenuation

Try these first

1. 1.

   What does attenuation refer to in seismic terms?

   Hint

   Think about how ground shaking changes as you move away from where the earthquake originates.

2. 2.

   What is Peak Ground Acceleration?

   Hint

   Consider what metric indicates the strength of shaking during an earthquake.

3. 3.

   What is the effect of distance on earthquake ground motion?

   • Increases motion
   • Decreases motion
   • Has no effect

   Hint

   Remember how the energy dissipates over distance.

4. 4.

   True or False: PGA is a measure of energy released at the earthquake's source.

   • True
   • False

   Hint

   Focus on what PGA specifically refers to in terms of measurement.

5. 5.

   A 7.0 magnitude earthquake occurs at a distance of 30 km from a city. Using the appropriate ground motion prediction equations, estimate the expected PGA, considering site conditions of soft soil.

   Hint

   Remember to account for the effects of soil type in your calculations.

6. 6.

   Discuss how variations in local geology can create differing levels of expected ground shaking in earthquake-prone areas, and how engineers can adjust designs accordingly.

   Hint

   Reflect on the relationship between geology and seismic energy propagation.