1. Locating Epicenters and Earthquake Depths
Cornell Notes page 133

2. Determining
distance from
seismograph to
epicenter
P waves and S waves travel at different speeds.
Time between when P wave arrives and when S wave arrives can be used to determine how far away the epicenter is from that station.

4. Using Triangulation
The seismograph can tell us how far away the EQ is, but not in which direction.
Must use at least 2 other stations to locate the epicenter.

5. Using Triangulation
1. Determine distance from station to epicenter.
2. Draw circle around station with radius = to distance.
3. Do the same for at least 2 other stations.
4. Place where all 3 circles meet is the epicenter.

7. Depth of Focus
Shallow focuses (less than 70km deep) are more destructive than deep focuses (over 300km deep).