HOW TO LOCATE AN EARTHQUAKE'S EPICENTER
HOW TO LOCATE AN EARTHQUAKE'S EPICENTER
The epicenter of an earthquake is the area on the surface directly above
the focus of an earthquake. By locating the epicenter seismologist can
determine where in the earth's surface the earthquake waves originate from.
This will help predicting and preparing for future quakes and hazards.
To locate the earthquake's epicenter you need a seismogram from three
separate seismic stations. Study the seismographs and find the elapsed time
between the arrival of the first P-wave and the first S-wave. By determining
the S-P time, and using a time-distance graph you can find the distance to
the epicenter from the seismic station. Now on a map draw a circle around
the epicenter, in which the radius of the circle equals the distance to
the epicenter. Draw circles around the other two seismic stations. the
point at which the three circles meet is the epicenter. In a effort to get
accurate earthquake readings the U.S. has created a world wide network of
over 100 seismic stations, operated through Golden, Colorado. The largest
station located in Billings, Montana, has 525 instruments grouped in 21
clusters covering a region of 200 k. in diameter. By using information
from the instruments in Billings, seismologist using high-speed computers
are able to locate an epicenter by a trial-and -error procedure.This is the Big One!
**This page was created by: Travis Griffin & Jason Perry**
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Email: perryjas@dekalb.dc.peachnet.edu
