Name: _______________
Block:__________________
Science 10 Lab Activity 18A – Where was that Earthquake?
Question: ___________________________________________________________________
____________________________________________________________________________
Experimental Design: In this experiment you will be taking data that has already been
collected and analyzing it to find the epicenter of an earthquake.
Materials: see page 532 of BC Science Probe 10.
Procedure: Follow the flowchart below
Find location of
each station on
map sheet
Conclusion:
Answer in
complete
sentences the
questions attached
Measure the time
difference between SP wave arrivals (S-P
lag time) found on
back sheet. Enter the
data below
The point at which all
the circles cross is
the location of the
earthquake
Interpolate from
graph (attached
sheet) the distance
to the epicenter.
Enter the data below.
Using the compass,
draw a circle around
each station that has a
radius equal to the
distance interpolated
from the graph
Data:
Location
S-P Time Lag (s)
Distance From Epicentre (km)
Conclusion: (Write in complete sentences)
1. Which seismograph was furthest from the epicentre? Which was the closest?
2. Where was the epicentre of the earthquake? Write as a distance from a major population.
3. How many seismograph stations are needed to locate an epicentre?
4. If zero on the seismograph indicates 5:35 am, determine the time that the earthquake occurred to the
nearest minute.
5. Currently scientists all over the world share their seismograph data using the Internet. Computers
analyze data from hundreds of seismographs. Describe how this amount of data sharing changes
the speed and accuracy with which earthquakes can be located.