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There are three seismic waves Primary P-Waves These waves move in a compress and expand motion They are the first to arrive to the epicenter Secondary S-Waves These waves vibrate in a side to side motion Surface L-Waves These waves move in an up and down circular motion Most destructive wave Continue to Seismogram

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The picture with the squiggly line is called a seismogram It measures how big the seismic waves are The seismogram is a piece of paper located on seismograph A seismograph measures the intensity of the earthquake at a certain location It does this by having a weight hold a pen as the earth shakes, the pencil stays still as a squiggly line is created The more shaking the bigger the lines The picture to the right is a seismograph Let’s see how we use this

This is when the P-wave arrives This is when the S-wave arrives The difference in time between when the P-wave arrives and when the S-waves arrives, also know as lag time. This is important because it will tell you how far away you are from the epicenter.

 A. Locate the how long the P-Wave shakes the seismogram. A. Locate the how long the P-Wave shakes the seismogram.  B. Find when the S-wave arrives, then the P- wave, and find the lag time between the two. B. Find when the S-wave arrives, then the P- wave, and find the lag time between the two.  C. Find when the P-wave arrives, then the S- wave, and find the lag time between the two. C. Find when the P-wave arrives, then the S- wave, and find the lag time between the two.  D. HELP!!D. HELP!!

This is when the P-wave arrives This is when the S-wave arrives The difference in time between when the P-wave arrives and when the S-waves arrives, also know as lag time. This is important because it will tell you how far away you are from the epicenter.

This is when the P-wave arrives This is when the S-wave arrives The difference in time between when the P-wave arrives and when the S-waves arrives, also know as lag time. This is important because it will tell you how far away you are from the epicenter.

CityP-wave Arrival Time S-wave Arrival Time Lag Time Washington DC2:102:111 hour New York2:142:173 minutes Chicago2:192:244 minutes CityP-wave Arrival Time S-wave Arrival Time Lag Time Washington DC2:102:111 minute New York2:142:173 minutes Chicago2:192:245 minutes

CityP-wave Arrival Time S-wave Arrival Time Lag Time Washington DC2:102:111 hour New York2:142:173 minutes Chicago2:192:244 minutes CityP-wave Arrival Time S-wave Arrival Time Lag Time Washington DC2:102:111 minute New York2:142:173 minutes Chicago2:192:245 minutes This is one should be 1 Minute This one should be 5 minutes

This graph is available at bryonspicci.sslpowered.com 1 st Step – Figure out the size of the lag time. Let’s use 1 minute as an example. 2 nd Step – Find where the P- wave and S- Wave have the measurement of the lag time. 1. This is how big one minute is 3 rd Step - find the distance below. 3. Your distance is about 300 miles 2.This is where the lag time is one minute I do not understand. Let’s move on

1 st Step – Figure out the size of the lag time. Let’s use 1 minute as an example. 2 nd Step – Find where the P- wave and S- Wave have the measurement of the lag time. 1. This is how big one minute is 3 rd Step - find the distance below. 3. Your distance is about 300 miles 2.This is where the lag time is one minute This graph is available at bryonspicci.sslpowered.com I do not understand. Let’s move on

This graph is available at bryonspicci.sslpowered.com Let say that at your location the P-wave arrives at 9:30 and the S-waves arrives 9:33, how far are you away from the epicenter? A B C D. 900

This graph is available at bryonspicci.sslpowered.com Let say that at your location the P-wave arrives at 9:30 and the S-waves arrives 9:33, how far are you away from the epicenter? A B C D. 900

This graph is available at bryonspicci.sslpowered.com Let say that at your location the P-wave arrives at 9:30 and the S-waves arrives 9:33, how far are you away from the epicenter? A B C D. 900

This graph is available at bryonspicci.sslpowered.com Let say that at your location the P-wave arrives at 9:30 and the S-waves arrives 9:33, how far are you away from the epicenter? A B C D. 900

Washington, DC New YorkChicago

Washington, DC Washington, DC is 900 miles away click on it New York is 1200 miles away click on it Chicago is 1900 miles away Click on it New York Chicago This is epicenter! Click here to take the quiz. Click here to take the quiz. I think I need more help before taking the quiz I think I need more help before taking the quiz

1.When locating the epicenter, the first thing someone must do is… A.Draw three circles B.Find the arrival time of the p-wave and s-wave C.Find the lag time D.Locate the focus 2.When locating the epicenter, the second thing someone must do is… A.Draw three circles B.Find the arrival time of the p-wave and s-wave C.Find the lag time D.Locate the focus 3.Lag time is the difference in time between the _________ and ___________. A. Seismic wave and tsunami B.P wave and T wave C.Shake and Aftermath D.P wave and S wave 4.After you find the distance a location is from the epicenter, you need to… A.Draw a circle and find the possible locations B.Draw a square and find the possible locations C.Call it a day D.Decide how big of a circle you need to draw around the epicenter 5.What is the minimum amount of locations you need to locate an epicenter? Write the answer in the box to the right. Click here when all questions have been answered