A POWERPOINT RELATED TO THIS WAS ALSO UPLOADED.tHIS IS FOR GRADE 10 STUDENTS 1ST QAURTER

1. Avtivity no. _______ Date: ____
Name: ____________________ Grade & Section: ____
Find the Center
Learning Competency: S10ES-Ia-j-36.1
Describe the distribution of active volcanoes, earthquake epicenters and major
mountain belts
Objective:
Locate the epicenter of an earthquake using the triangulation method.
KEY CONCEPTS:
->Epicenter is a point on the surface of the Earth directly above the FOCUS of an
earthquake.
-> To locate epicenter using triangulation method, the following data must be provided
1.At least three(3) recording stations
2. Time difference in the arrival of P-wave and S-wave in each station
3. Distance of epicenter from each station
Materials:
• hypothetical records of earthquake waves • Philippine map • drawing compass and
ruler
Procedure:
1. Fill in the table using the formula provided.
Recording station Time difference in the
arrival time of P-wave
and S-wave
(seconds)
Distance of epicenter
from the station (km)
x
Computed
distance on the
map
Map distance(cm)
=d/200 * 1.1
Batangas 44.8
Puerto Princesa 32
Davao 38.4
2. On the map below, use the computed distance on map in each station to locate the
epicenter. Start measuring the distance from Batangas (orange dot) and form a circle
using a drawing compass. If you don’t have a compass, you can draw a circle using a
string,clip,etc. Watch here for a hack on how to draw a circle without using compass.
https://www.youtube.com/watch?v=4EFA4YLSMHA
3.Do the same for puerto Princesa and Davao.
Q1. Where is the epicenter of this hypothetical earthquake?(place where 3 circles
intersect)

2. Q2. What difficulty will you encounter if you only have data from two
recording stations?
Q3. What is the distance of the epicenter from the seismic station?
Q4. What do you think is the importance of determining the epicenter of an
earthquake?
Prepared by: DARYL F. CADANILLA