Physical Geology (GOL 105)
40 points possible
EARTHQUAKES & SEISMOLOGY
To prepare for this lab, please read Chapter 16 in your lab manual and
Chapter 11 in your textbook.
Familiarize yourself with the typical “anatomy” of a seismogram using the following example.
1) On page 395 of the lab manual, you are provided with P-, S-, and L-wave travel times for
seismographs at nine locations, all for this one New Guinean earthquake. You won’t necessarily
know which measurement refers to which wave until you plot them all on the accompanying
graph paper. Once all the data have been recorded, you should draw three “best-fit” curves to
show the travel-times for P-waves, S-waves, and L-waves. (P will be fastest, L slowest, and S
somewhere in between.) Figure 16.5 (page 395) in your lab manual can serve as a guide, but you
must plot the data yourself. If you wish to plot the data using a spreadsheet program (such as
Microsoft Excel), that’s fine too. Just attach your graph to the lab as a new page when you submit
it for grading.
Distance to epicenter (kilometers)
Travel time (minutes)
10 11 12 13 14 15
22 23 24
2) Now examine the three seismographs below. Only P- and S- waves are shown (not L). For each,
determine the time the first P-wave arrived, the time the first S-wave arrived, and then the S-minus-P time
(expressed in minutes and seconds). Fill these...