SEQ CHAPTER \h \r 1Geol 210: Homework #2 Name _______________________

Locating Earthquakes and Measuring Their Magnitude

The figure below shows seismograms for the same earthquake that were recorded at 3 different locations (Fontana, Kramer Junction, and CSUSB). The horizontal axis is time. Each tick mark represents one second, and selected times are labeled in hours:minutes:seconds. The vertical axis is amplitude of shaking, and the amplitude scale is shown next to the seismogram recorded at CSUSB.

1) Mark with an arrow the arrival of the p-wave, the s-wave, and the surface wave on each of the 3 seismograms

2) From the seismograms, calculate the time delay between the arrival of the p-waves and the arrival of the s-waves at each station and write your answers in the table below.

 Station S wave arrival time P wave arrival time Time delay between S & P Distance to earthquake Fontana Kramer Junction CSUSB

3) Using the diagram below and the time delay between the arrival of the p-waves and the s-waves, calculate how far away the earthquake was from each of the three stations, and write your answers in the table on the previous page.

4) What was the maximum amplitude of shaking at the CSUSB station? ___________

5) Using the maximum amplitude of shaking at CSUSB and the time delay between the p and s waves at the CSUSB station, use the diagram below to calculate the magnitude of this earthquake.

6) Use the distance of the earthquake from each of the 3 stations in your table (Fontana, Kramer Junction and CSUSB) to plot the location of the earthquake.