3. Elastic Rebound Theory 3 m offset

4. Earthquake Focus and Hypocenter

5. Seismic Wave Types Body Waves Surface Waves

6. V p = k + 4/3µ  1/2 equations for velocities  density µ shear modulus (rigidity) k bulk modulus (rigidity) V s = µ  1/2 because shear modulus (rigidity) for fluid is zero, S waves cannot propagate through a fluid consequence of equations is that P waves are 1.7x faster than S can infer physical properties from P and S waves

8. Vertical Component Seismometer

9. Horizontal Component Seismomter

10. Distance - Time Relations

11. Earthquake Location by Range

13. Modified Mercalli Intensity Index (1931) 1886 Charleston, SC earthquake

14. Pancaked Building - 1985 Mexico City Earthquakes don’t kill people - buildings do!