Epicenter

1. Epicenter
Location
32R

2. Epicenter Location
When an EQ happens, it travels in all
directions from the focus

3. Epicenter Location
If you feel an EQ, you won’t know which
direction it came from
???

4. Epicenter Location
To locate epicenter, need:
3 EQ stations
Seismogram recordings
Difference in time between P and S-wave

6. Epicenter Location
The difference in arrival times of P-waves and
S-waves tells you how far away epicenter is
Difference in
time?
4-1 = 3 seconds

7. Epicenter Location
The difference in arrival times of P-waves and
S-waves tells you how far away epicenter is
The longer the time, the further away from EQ
4-1 = 3 seconds

8. Which city is
closest to the
earthquake?
Which
earthquake is
the furthest?

9. 6 minutes
2 minutes
4 minutes
3 minutes
Which earthquake is the closest? Furthest?
Time
difference

10. 6 minutes
2 minutes
4 minutes
3 minutes
Which earthquake is the closest? Furthest?
Time
difference

11. The data below is
a recording for an
EQ at one of these
epicenters (A-D).
Which one is it?

12. The data below is
a recording for an
EQ at one of these
epicenters (A-D).
Which one is it?

13. The data below is
a recording for an
EQ at one of these
epicenters (A-D).
Which one is it?

14. Which city is
closest to the EQ?

15. LA, then Santa
Barbara, then
Palmdale, then
San Bernardino

16. Which EQ did all
four
15 seconds
40 seconds
41 seconds
56 seconds