# Wednesday April 18, 2012

```Wednesday April 18, 2012
DO NOW: Be sure your ISN entries for this week are:
 Exploring the USGS- 4/16
o Both left and right sides- notes from USGS handout
 Virtual Earthquake (tutorials)- 4/16
o Left side (S-P interval)- questions #1-4 in complete sentences
o Right side (Latitude and Longitude)- questions #1-7 in complete sentences
 Virtual Earthquakeo Left side- Travel time- 4/17- journal should be taped here
o Right Side- Epicenter and Magnitude- will do today 
NEXT: Create a new ISN entry titled “Locating the Epicenter”
Record the following notes in your ISN on the RIGHT SIDE:
Triangulation- using S-P lag time recorded at three different seismic stations, distance can be
determined on a travel time curve. These distances are used to measure the radius around
each seismic station in order to locate where they intersect, indicating the epicenter of an
earthquake.
Amplitude (A max)- the height of a wave.
Magnitude- a quantitative measurement of the energy released by an earthquake.
(Richter magnitude- when magnitude increases 1 unit, A max increases 10X)
Richter nomogram- a graph representing the relationship between the maximum S-wave
amplitude, distance to epicenter, and Richter magnitude.
CLASS DEMONSTRATION OF TODAY’S VIRTUAL EARTHQUAKE LAB: EPICENTER AND
MAGNITUDE

After you complete the “Epicenter and Magnitude” activity, print out the journal and tape
into your ISN (on the right side opposite yesterday’s S-P lag time activity)

Then take the “Virtual Earthquake Quiz” You will be asked for your name and School.
Please just put your first name and last initial and “6th grade science” for the school. You
do not need to put any code in when prompted.

Print out the certificate that follows and add that to your ISN as well. You can create
another right and left side titled “Virtual Earthquake Wrap Up”. Tape the certificate to the
right side. On the left you will answer this:

Describe (in detail) how you used seismograms to determine the epicenter and
magnitude of an earthquake. If necessary, go back to the “Virtual Earthquake” activity