1. How can we use seismic wave velocities to locate Earthquake Epicenters?

2. Using Distances to known Earthquake epicenters, create
Time – Travel Curves

3. Use Time – Travel
Curves to calculate
Distances to Quake in an unknown location.

4. TRIANGULATE EPICENTER

6. Earthquake Epicenters Around The World
Random Epicenters?
What does map remind you of?

7. FOCUS (DEPTH) DISTRIBUTION
RANDOM?

15. Earthquake Intensity Measures
Modified Mercalli Intensity Scale
Earthquake Intensity Measures
Modified Mercalli Scale – Based on perception of shaking and amount of destruction

17. Based on the largest amplitude wave on seismogram
2) Richter Scale
Based on the largest amplitude wave on seismogram

18. Richter Scale
A Logarithmic Scale: each number is 10X greater than previous number. Energy release is  32X greater.
Wave amplitude is based on amount of shaking – dependent in part on rock type. Shaking also decreases with distance.
Distance of seismograph station must be standardized.
Richter Scale doesn’t measure very large quakes accurately in terms of energy release.

19. 3) Moment Magnitude Scale – Measures energy released by rock rupture.
Based on:
Amount of Slip X Area of Rupture X Elastic Rebound of Rock

20. Energy released
by Earthquakes