do now power on your laptops and download the earthquake ps wave travel time notes. please take out...
TRANSCRIPT
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!!
Topic: Seismic Wave Travel Topic: Seismic Wave Travel TimeTime
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Page 11Page 11
Using the scaleUsing the scale x10x1033 km = 1000 km km = 1000 km
Th
e
Th
e
Ep
icen
ter
Ep
icen
ter
3000 k
m
3000 k
m
from
fro
m
ep
icen
ter
ep
icen
ter
1200 k
m
1200 k
m
from
fro
m
ep
icen
ter
ep
icen
ter
7000 k
m
7000 k
m
from
fro
m
ep
icen
ter
ep
icen
ter
4400 k
m
4400 k
m
from
fro
m
ep
icen
ter
ep
icen
ter
Time unit is minutesTime unit is minutes
1 minute = 60 1 minute = 60 secondsseconds
0 0 secondsseconds
60 60 secondsseconds
20 20 secondsseconds
40 40 secondsseconds
8 min, 00 sec8 min, 00 sec
11 min, 40 sec11 min, 40 sec
3 min, 20 sec3 min, 20 sec
5 min, 30 5 min, 30 secsec
P waves
S waves
Epicenter
How long does it How long does it take for a P wave take for a P wave
to travel 4000 to travel 4000 km?km?
7 minutes7 minutes
How long does How long does it take for an S it take for an S wave to travel wave to travel
4000 km?4000 km?
12 min 40 sec12 min 40 sec
How far does an How far does an S wave travel in S wave travel in
21 minutes?21 minutes?
8200 km8200 km
How far does an How far does an P wave travel in P wave travel in
6 minutes 20 6 minutes 20 seconds?seconds?
3500 km3500 km
If the epicenter If the epicenter is 2000 km is 2000 km
away, and the P away, and the P wave is wave is
recorded at recorded at 5:04 am, what 5:04 am, what time did the time did the earthquake earthquake
occur?occur? 5:04 am – 4 min 5:04 am – 4 min = 5:00am= 5:00am
Final Question:Final Question:
• How much further does a P wave How much further does a P wave travel in 8 minutes than an S wave travel in 8 minutes than an S wave does?does?
P wave = 4800 P wave = 4800 kmkm
S wave = 2200 S wave = 2200 km km
Difference = Difference = 2600km2600km
Topic: How to Find The Topic: How to Find The Distance From an EpicenterDistance From an Epicenter
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Page 11Page 11
2:30:00
2:36:00
The time different is 6 minutes
• We don’t know We don’t know when the when the earthquake started.earthquake started.
• We do know the We do know the difference between difference between the P&S wave the P&S wave arrival times.arrival times.
• 00:06:00 minutes00:06:00 minutes
• Find where Find where P&S are P&S are separated separated by 6:00 by 6:00 minutes.minutes.
• The distance The distance to the to the epicenter epicenter from the from the seismograph seismograph is 4400 km.is 4400 km.
Final Question:Final Question:
• If a P wave arrives at 6:32 pm at the If a P wave arrives at 6:32 pm at the seismograph, and the S wave arrives seismograph, and the S wave arrives at 6:34 pm, What is the distance to at 6:34 pm, What is the distance to the epicenter?the epicenter?
1400 km
P-wave AT = 6:32 AM
S-wave AT = 6:34 PM
Difference = 0:02 Min
Epicenter Distance = 1400 km