1. Reading a Seismograph

2.  If a P-wave arrives at station A at 9:08, how do we correctly write the time? ________ : _________ : ________  If an S-Wave arrives at station A at 9:15, how do we correctly write the time? ________ : _________ : ________

3.  AIM: How can you use a graph of earthquake waves’ travel distance and time to find an epicenter?  Learning Target: I can use observational data to solve for the earthquake epicenter.  Agenda Catalyst Mini lesson Practice

4.  An instrument that measures motion beneath the ground

5.  Time is on the X axis

6.  Step 1: When do S waves arrive?  S arrives at: 9:15

7.  Step 2: When do P waves arrive?  P arrives at: 9:08

8.  Step 3: What is the difference in arrival times?  Find the difference  9:15  -9:08  7 minutes

9.  Steps:  1. Find difference in arrival time  2. Using the graph, make a mark on your paper  3. slide your paper VERTICALLY until that mark matches the space in between  4. Read the x – axis to find the distance.

10. Example: If the difference in arrival time between P and S waves is 7 minutes and 00 seconds, how far away did the earthquake begin?

14. Difference in Arrival Time Distance from Epicenter 7:00 minutes

15. Example: If the difference in arrival time between P and S waves is 2:40, how far away did the earthquake begin?

18. Difference in Arrival Time Distance from Epicenter 7:00 minutes5.0x10 3 Km 2:40 minutes

19. S-waves: ___9 ____ : ____27_____ : ___00___ P-waves: ____9___ : ____24_____ : ___00___ Difference: _______ : _________ : ______ Distance: _____________ kmS

20. S-waves: _______ : _________ : ________ P-waves: _______ : _________ : ________ Difference: _______ : _________ : ________ Distance: _____________ km

21.  Inclass and Complete if not finished: Complete the Page in Your Unit Packet Labeled:  Finding Epicenters  ONLY DO SIDE 1