1. Do Now Power on your laptops and download the earthquake PS wave travel time notes. Please take out your reference tables. H.W. Continue your castle learning assignment questions 31 – 36. Reminder: –The 3 rd quarter ends next Friday. All missing work must be in by then or the ZERO stays!!

2. Topic: Seismic Wave Travel Time

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7. Using the scale x10 3 km = 1000 km The Epicenter 3000 km from epicenter 1200 km from epicenter 7000 km from epicenter 4400 km from epicenter

9. Time unit is minutes 1 minute = 60 seconds 0 seconds 60 seconds 20 seconds 40 seconds

10. 8 min, 00 sec 11 min, 40 sec 3 min, 20 sec 5 min, 30 sec

11. P waves S waves Epicenter

12. How long does it take for a P wave to travel 4000 km? 7 minutes

13. How long does it take for an S wave to travel 4000 km? 12 min 40 sec

14. How far does an S wave travel in 21 minutes? 8200 km

15. How far does an P wave travel in 6 minutes 20 seconds? 3500 km

16. If the epicenter is 2000 km away, and the P wave is recorded at 5:04 am, what time did the earthquake occur? 5:04 am – 4 min = 5:00am

17. Final Question: How much further does a P wave travel in 8 minutes than an S wave does?How much further does a P wave travel in 8 minutes than an S wave does?

18. P wave = 4800 km S wave = 2200 km Difference = 2600km

19. Topic: How to Find The Distance From an Epicenter

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21. 2:30:00 2:36:00 The time different is 6 minutes

22. We don’t know when the earthquake started.We don’t know when the earthquake started. We do know the difference between the P&S wave arrival times.We do know the difference between the P&S wave arrival times. 00:06:00 minutes00:06:00 minutes

23. Find where P&S are separated by 6:00 minutes.Find where P&S are separated by 6:00 minutes. The distance to the epicenter from the seismograph is 4400 km.The distance to the epicenter from the seismograph is 4400 km.

24. Final Question: If a P wave arrives at 6:32 pm at the seismograph, and the S wave arrives at 6:34 pm, What is the distance to the epicenter?If a P wave arrives at 6:32 pm at the seismograph, and the S wave arrives at 6:34 pm, What is the distance to the epicenter?

25. 1400 km P-wave AT = 6:32 AM S-wave AT = 6:34 PM Difference = 0:02 Min Epicenter Distance = 1400 km