Virtual Earthquake Activity
Introduction:
Virtual Earthquake is an interactive Web-based activity designed to
introduce you to the concepts of how an earthquake EPICENTER is located and how
the RICHTER MAGNITUDE of an earthquake is determined. Virtual Earthquake will
show you the recordings of an earthquake's seismic waves detected by instruments
far away from the earthquake. The instrument recording the seismic waves is called
a seismograph and the recording is a seismogram. The point of origin of an
earthquake is called its focus and the point on the earth's surface directly above the
focus is the epicenter. You are to locate the epicenter of an earthquake by making
simple measurement on three seismograms that will be sent to you by the Virtual
Earthquake program. Additionally, you will be required to determine the Richter
Magnitude of that quake from the same recordings. Richter Magnitude is an
estimate of the amount of energy released during and earthquake.
Upon completion of this activity you will be given the opportunity to receive
a personalized Certificate as a "Virtual Seismologist.” In order to get this
certificate, you must make careful measurements throughout the activity.
Activity:
1. Open your web browser to the following link:
http://www.sciencecourseware.com/VirtualEarthquake/
2. Scroll to the bottom of the first page and click on the button that says,
“Execute virtual earthquake” to begin.
3. Read information on this page and answer the questions below.
a. Where do most earthquakes occur?
b. What are seismic waves?
c. What two types of seismic waves are we using in this activity? How
fast do they travel?
d. Reproduce (Draw) the example of the simplified seismogram. Label
the P waves and the P-wave arrival time, S-waves and the S-wave
arrival time, the S-P interval, and the S-wave maximum amplitude.
e. How many seismic recording stations do we need to use to locate an
epicenter of an earthquake? Why?
4. After you have answered the previous questions pick and earthquake from
the four listed and click on “submit choice”.
5. Read through the information on this page, when done click “view
seismograms”.
6. Use the three seismograms to estimate the S-P time interval for each of the
recording stations. Record your measurements in the box below each
seismogram. When done click “convert S-P interval”.
7. Read through the information on this page. When done use the information
you calculated on the previous page and the S-P graph to calculate the
distance in kilometers each station was away from the epicenter. When done
click “Find epicenter”.
8. Were you right? If you get an “Ooops” response click on “re-measure S-P
interval” to figure out your mistake. If you get “very close” you may click “remeasure S-P interval” to figure out your mistake or “Show true epicenter” to
continue. If you get “Excellent work” you may continue to the magnitude
portion of the activity by clicking “Compute Richter magnitude”.
9. Read through the information on this page and answer the following
questions below.
a. What is the magnitude of an earthquake?
b. What is the minimum Richter Magnitude that most people feel?
c. What two pieces of information do you need to estimate Richter
magnitude?
10. Read through the information on this page and click “Go to next page”.
11. Measure the maximum amplitude of the S-wave for each seismogram and
record your estimate in the box below each seismogram. When done click
“Submit to Nomogram”.
12. Use the diagram and estimate the Richter magnitude of this earthquake. Your
line may not cross exactly. Record the Richter magnitude in the box provided
and click “confirm magnitude”.
13. If you see “Congratulations! You’ve done a great job.” Then you have
completed the exercise. Enter your name, school (institution), city and state.
Click on email certificate to instuctor and enter my email
mrfazio@californiascienceteacher.com you can also email it to yourself if you
want. Then click “Get certificate”.
14. How well did you do? Check your results with the actual results.
15. If time permits click “execute earthquake” to complete one of the other
earthquakes for extra credit. Otherwise turn in answers to questions to your
teacher and return this packet.