Name _____________________________ Date ____________________ Period_______
Transform Fault Lab - Earthquake Epicenters
1. Study the three seismograms on page 4. Which seismic station is closest to the
earthquake epicenter? ______________________________________________
Which is furthest away? ____________________________________________
2. Determine the distance from each seismic station to the epicenter by the following
steps:
A. Examine the seismograms and determine in seconds the time interval between
the P and S wave arrivals.
Time in Seconds Between P and S waves:
Sydney _______sec
Tokyo ________sec
Honolulu ________sec
B. Locate the time scale on the Travel Time Graph on pg 4. Line the corner of
this page up with the corner of the graph and place a mark on this page at each
time in seconds.
C. Keeping corner points lined up slowly turn this page until marked off
distances fits exactly between the P and S waves. Put at dot at each location
between the P and S waves.
D. Follow the dot down to the distance axis at the bottom. This value is the
epicenter to each station.
Distance from Epicenter:
Sydney _________ km
Tokyo _________ km Honolulu ___________ km
3. Use the map scale to set a drafting compass to the proper length for the distance
from Sydney to the epicenter. Place the compass point at Sydney and draw an arc
using the distance as the radius. Repeat for Tokyo and Honolulu. The intersection
of the three arcs marks the epicenter of the earthquake.
Epicenter Location:
Latitude ______________________
Longitude __________________________
4. List any geographical features associated with the epicenter.
_____________________________________________________________________
5. Look at the plate boundary map. What do you notice about where your
geographical features are located?
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Name _____________________________ Date ____________________ Period_______
Name _____________________________ Date ____________________ Period_______