EarthQuakes Simulation Activity
Name _______________________________________
Date ______
Observe animations of earthquake waves
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1002/es1002page01.cfm?ch
apter_no=visualization
Click the images to see the animations. Play both movies at the same time to examine the relative speeds
of the waves.
Describe the differences and similarities of the two main types of earthquake waves. Define each type of
wave!
P waves - ___________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
S waves - ___________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
Examine P and S waves moving through Earth's interior
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1009/es1009page01.cfm?ch
apter_no=visualization
Click the image to see the animation. Use the movie controls to examine the motion of the waves.
Describe the differences and similarities of the two main types of earthquake waves as they move through
the structure of the Earth.
P waves - ___________________________________________________________________________
___________________________________________________________________________________
S waves - ___________________________________________________________________________
___________________________________________________________________________________
World Series Earthquake
http://www.classzone.com/books/earth_science/terc/content/investigations/es1003/es1003page01.cfm?c
hapter_no=investigation
On October 17, 1989 at 5:04 P.M., a major earthquake struck the San Francisco Bay area. The earthquake
was nicknamed the World Series Earthquake because it occurred just before a World Series baseball game
was scheduled to begin in Candlestick Park. Millions of people witnessed the motion of the earthquake on
television. Sixty-seven people lost their lives, and property damage was estimated at $6 billion.
Click each image to see some of the destruction caused by this earthquake. Describe at least 3 types of
damage caused by the earthquake.
1. _________________________________________________________________________________
2. _________________________________________________________________________________
3. _________________________________________________________________________________
Damage from the earthquake was widespread, but the actual location of the earthquake (the epicenter)
was reported almost immediately. With damage all around, how could geologists accurately identify the
epicenter of the earthquake?
In this investigation, you'll see an example of how the World Series Earthquake's epicenter was located;
then you'll use data from another earthquake in California to locate its epicenter.
Locating the World Series Earthquake Epicenter
P and S waves generated by the World Series Earthquake traveled away from the epicenter and were
recorded at the three locations on the map below.
Click each city on the map to see the seismogram and travel-time graph for that location. Interpret the
graph to find the distance from the recording station to the epicenter, and answer number 1 below. If
necessary, review the Time for an Earthquake notes and use you ESRT!
1. What do you notice about the time interval between the arrival of P and S waves at the three different
seismograph stations? What causes these differences? ________________________________________
____________________________________________________________________________________
Using the known distance to the epicenter from three different locations, circles with radii of the indicated
distance are drawn around each of the recording cities. The place where the three circles intersect is the
called the __________________________________________.
Click the buttons for each city below the graphic to show a circle indicating the distance to the epicenter.
The intersection of the three circles is the epicenter location.
The three circles intersect near the city of ___________ _________, California, so this city was the
epicenter of the earthquake. Thus, the World Series earthquake is also known as the _________
_________ earthquake.
Distance to the Epicenter from Three Recording Stations
On January 17, 1994, at 4:30 A.M., a major earthquake shook the Los Angeles metropolitan area. Again,
the damage was widespread. You'll use the map below and seismograms from three recording stations to
locate the epicenter. The map shows freeways (labeled yellow lines) and known faults (unlabeled lines of
various colors) in the area surrounding Los Angeles.
Click the red dots on the map to view the seismogram and travel-time graphs recorded at each location.
Interpret each graph to read the distance to the epicenter from that location.
2. For each location, record the distance to the epicenter.
Lancaster ________________________
Victorville ________________________
Los Angeles ________________________
Intersecting Circles Identify the Epicenter
Now you'll use each of the distances you recorded for question 2 as the radius of a circle around the
recording city. The location where the three circles intersect is the epicenter.
Follow the instructions on the left to draw circles of the appropriate size around each recording city.
Record your answer on the map on your student answer sheet.
3. For each location, draw circles corresponding to the distances you recorded in question 2. Sketch the
circles on your map and mark the epicenter location.
Damage from the Northridge Earthquake
The intersection of your circles should have been at Northridge, a community northwest of Los Angeles.
This was the first major earthquake to strike this urban area since 1933. It caused mass destruction of
buildings and highways. Sixty people died from injuries suffered in the earthquake, and property damage
was estimated at $20 billion.
Click each image to see photographs of damage caused by the Northridge earthquake.
4. Describe three different examples of damage that occurred as a result of the Northridge earthquake.
1. _________________________________________________________________________________
2. _________________________________________________________________________________
3. _________________________________________________________________________________