8.22: Assignment- Earthquakes
In this assessment, you will read and interpret various seismograms to determine the location of an earthquake. You will also determine the magnitude of the earthquake. When you are finished you will be presented with a Certificate of Completion making you a Virtual Seismologist. Remember to access the tips and hits at the bottom of the page.
Basic Requirements (assignment criteria):
- Go to the Virtual Earthquate (Links to an external site.) site from Geology Labs online.
- Choose a location to “experience” your earthquake.
- Read over the next page on how to determine the P-S wave time interval from a seismogram.
- On the next page you will view three different seismograms. Determine the time difference from the P wave to the arrival of the S wave on each seismogram and enter it into the box.
- Click on the convert button to go to the next page.
- Use the bottom graph to get the epicenter distance. For example, if you have stated that the S-P interval is 35 seconds, you will find 35 seconds on the vertical (y-axis) and follow it across until it intersects the diagonal line. Then draw your line straight down to the horizontal line (x-axis) to get the distance. In this case, 35 seconds translates to 340 Km. Another example, 51 seconds is 500 Km. You will enter these values in the box on the right.
- Click on find epicenter. Depending on well you did, you can either re-enter your data to try again or click View True Epicenter if you are close.
- When you get close, go click on the View True Epicenter, look at how close you came to the true epicenter. Take a screenshot of the two pictures and save them for later.
- Click on Compute Richter Magnitude. Read the explanation of magnitude, then go to the next page. Read about the nomogram and how to use it.
- Go to the next page and complete the questions on magnitude. Click submit and proceed to the nomogram of your data.
- Answer the magnitude estimate and then click on confirm magnitude. If you were successful you will have a screen congratulating you.
- Fill in the necessary information to get your certificate, make sure you DO NOT email a copy to me. Click get certificate and you will see a green certificate and chart.
- Take a screen shot and save this for later.
- Open up a word document and insert both the picture of your earthquake location (the two side-by-side pictures) and the picture of your completion certificate and chart. Adjust them to fit on one page.
Answer the following questions on the same page:
- Based on the location and magnitude of your earthquake, speculate on the type of damages your earthquake might have caused.
- Now compare this to the Mercalli Intensity scale. What classification is your earthquake based on this scale?
- How did the different waves (P, S & Surface Waves) assist you in determining the epicenter and the amount of damage caused?
- Was your location in an area prone to earthquakes? Speculate on what might have caused this earthquake (be specific).
- Why is it so difficult for geologists to predict when and where an earthquake will occur?
- What connections can you make between the behavior of the seismic waves and the Earth’s interior?
- Make sure your name is ON your document before submitting.
Tips and hints can be found here (Links to an external site.) .
This assessment is adapted from “Virtual Earthquake” by Gary Novack, originally found here (Links to an external site.) .
Contributors and Attributions
- Earthquakes Assessment. Authored by : Kimberly Schulte. Provided by : SBCTC. Located at : http://www.columbiabasin.edu . License : CC BY: Attribution