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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!!.
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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 3rd quarter ends next Friday. All missing work must be in by then or the ZERO stays!!
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Using the scale x103 km = 1000 km 1200 km from epicenter 3000 km from epicenter 7000 km from epicenter 4400 km from epicenter The Epicenter
Time unit is minutes 1 minute = 60 seconds 60 seconds 40 seconds 20 seconds 0 seconds
11 min, 40 sec 8 min, 00 sec 5 min, 30 sec 3 min, 20 sec
S waves P waves Epicenter
How long does it take for a P wave to travel 4000 km? 7 minutes
How long does it take for an S wave to travel 4000 km? 12 min 40 sec
How far does an P wave travel in 6 minutes 20 seconds? 3500 km
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
Final Question: • How much further does a P wave travel in 8 minutes than an S wave does?
P wave = 4800 km S wave = 2200 km Difference = 2600km
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2:36:00 2:30:00 The time different is 6 minutes
We don’t know when the earthquake started. • We do know the difference between the P&S wave arrival times. • 00:06:00 minutes
Find where P&S are separated by 6:00 minutes. • The distance to the epicenter from the seismograph is 4400 km.
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?
P-wave AT = 6:32 AM S-wave AT = 6:34 PM Difference = 0:02 Min Epicenter Distance = 1400 km 1400 km