FELT Was Developed Through the Cyberteam Project

TechQuest 1: Practice/Exploration

Lesson Author: Susan Glassett

FELT was developed through the CyberTEAM Project

in collaboration with Scripps Institution of Oceanography

Practice/Exploration Activities

General instructions:

Exercise #1 (http://projects.cs.csusm.edu/maps/quakesDemoMode.html)

This exercise focuses on helping students recognize the fact that three seismic stations are needed to pin-point the epicenter of an earthquake. By clicking on the triangles (seismic stations), students will have a chance to answer questions with regards to how seismic stations help identify epicenters. For each triangle (station) a student clicks, FELT will draw a circle using the distance between the epicenter and the station as its radius. Only after three stations have been clicked will the software identify the epicenter of the earthquake.

Students will first be given a list of recent earthquakes from which they can select an earthquake of their interest. Once an earthquake is selected, students will be presented with a collection of seismic stations on a Google Map interface so that further exploration on seismograms recorded by those stations can be conducted. The triangles are used to represent seismic stations. Students are to click on the triangles of their choice to conduct their investigations.

In this exercise you will be shown how a seismologist’s use data collected from scientific instruments to precisely locate the epic center of an earthquake.
Open the FELT tool link which is found at:
http://projects.cs.csusm.edu/maps/quakesDemoMode.html
Choose an Earthquake location and click Start /
Teacher will experience the tool from the roll of a student
You will now be shown a map with various stations marked on it. Each stations is marked with a triangle(Δ).
Your purpose is to find the epicenter of the earthquake.
A click on an empty triangle will reveal a circle whose center is the station clicked and whose radius is the distance from the station to the epicenter. A click on a filled triangle will remove the circle whose center is the station clicked.
/
Exploring the screen /
Now, click any triangle (seismic station) to begin using the tool. Read the prompt and select the answer at the bottom of the prompt screen. Make note that the image on the prompt is an example, you want students to look at the seismogram in the bottom right corner. /
Select a 2nd triangle after answering the prompt and radius represents the distance from the epicenter. /
Select a 3rd triangle and the epicenter will be presented.
Congratulations! You have located the epicenter of your chosen earthquake.

If you move your mouse pointer over it will display the location of the epicenter (longitude, latitude) /

Exercise #2 (http://projects.cs.csusm.edu/maps/quakesDIYMode.html)

This exercise allows students to explore actual seismograms recorded at the stations. For each station, students are asked to move two vertical bars along the seismogram to mark the arrival of the Primary (P) and Secondary (S) wave front. Visual and audio hints are provided for students to correctly place the marks. Since FELT purposely selects stations that are azimuthally well distributed around the earthquake epicenter, students will have the opportunity to compare and contrast seismograms for the same earthquake that are recorded at different stations. Once students complete the marking of the P- and S-wave arrivals on a seismogram, FELT will calculate

You will begin the activity by first selecting the earthquake. When the position P & S markers appear, drag the “P & S” marker until the Hint Button fills with a color then click submit. You will do this three times to again locate the Epicenter.

Exercise #3 (http://projects.cs.csusm.edu/maps/quakesDIYTest.html )

This exercise further challenges students on the subject of epicenter identification. Similar to the second exercise, students will be asked to move the two vertical bars on seismograms to mark the P- and S-wave arrivals. Instead of having the computer calculate and display the distance between the epicenter and the station based on the time associated with the markings, students will be required to perform the calculation and determine the distance. In addition, students will need to adjust the size of the circle on the Google Map interface to match the distance they determine.

Next you position the circle based on calculated distance, repeat if you want.

URL: www.csusm.edu/cyberteam/