This document provides instructions and data for an activity to locate the epicenter of a hypothetical earthquake using triangulation based on data from three recording stations. The data includes the time difference between arrival of P and S waves and distance of the epicenter from each station. Students are asked to determine the epicenter location from the data, discuss difficulties with only two stations, and importance of determining epicenter locations.

1. Name:____________________________________________________________ Date:________________________
Section:___________________________________________________________ Teacher:_____________________
Activity 1
FIND THE CENTER
Objective:Locate the epicenterof anearthquake usingtriangulationmethod.
Recording Station
Time difference (td) in the
arrival of P-wave and S-
wave (seconds)
Distance of epicenter from
the station (km)
d = 100(td/8)
Conversion
(Scale – 1.5 cm:200 km)
𝑋
1.5 𝑐𝑚
200 𝑘𝑚
Batangas 44.8
Puerto Princesa 32
Davao 38.4
TABLE 1
Questions:
1. Where isthe epicenterof thishypothetical earthquake?
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2. What difficultywillyouencounterif youonlyhave datafrom tworecordingstations?
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3. What do youthinkisthe importance of determiningthe epicenterof anearthquake?
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