Name: ____________________________________________________
Period: ___
Scale Drawing of the Earth
Introduction:
The Earth is a complex, multi-layered ball of rock. When earthquakes occur they send waves of energy
through the Earth, in the same way that a large object breaking sends waves of sound through the air.
However, the earthquakes do not pass straight through the Earth. They bounce off the layers because
they are composed of different materials with different densities. Scientists are able to measure the
changes in the earthquake waves and predict what the structure of the inside of the Earth is. In this
activity, your group will be drawing a scale model of the Earth to give you an idea of the relative sizes of
each of the layers.
Materials:
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1x piece of butcher paper
1x meter of string
1x ruler
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1x marker
1x calculator
Instructions:
1) Our model will be 1/60,000,000th the size of the real Earth. Calculate the scale sizes of the parts
by dividing the values given in kilometers by 60 and filling in what they will be in centimeters.
Write your answers in the “Our Model Thickness (cm)” column of the tables below.
2) Find the center on the short side of your piece of paper and put a dot there.
3) Measure out a length on your string equal to the thickness you calculated in #1. Tie one end of
the string around a pencil and draw a semi-circle, using the dot from #2 as the center.
4) Make a new semi-circle for each layer of the Earth.
5) As you go, add up the thicknesses and add them together to fill in the “String Length (cm)”
column. DO NOT just measure a length of string equal to “Our Model Thickness (cm)” or your
drawing will be incorrect.
6) Add the surface features last.
7) Now label each layer with its name, density, phase, and main elements listed in Table 3. Include
units.
Data:
Table 1: Layers of the Earth
Earth Layer
Real Thickness (km)
Inner Core
1255
Outer Core
2220
Mantle
2895
Crust
40
Our Model Thickness
(cm)
String Length (cm)
Table 2: Surface Features
Feature
Real Height/Depth (km)
Orbit of Space Shuttle
300
Mt. Everest
8.8
Grand Canyon
1.7
Deepest Well
8
Mariana Trench
11
Our Model Size (cm)
Table 3: Layer Information
Layer
Inner Core
Outer Core
Mantle
Density (g/cm3)
12.7-13.0
9.9-12.1
3.3-5.5
Crust
2.7-3.0
Phase
Solid
Liquid
Solid and semi-solid
(“plastic”)
Solid
Main Elements
Iron
Iron, nickel
Magnesium, iron,
silicon
Silicon, magnesium,
aluminum
Questions:
1) Which layer of the Earth is the thickest? Which is the thinnest?
2) If you saw the Earth from space, would it appear smooth or bumpy?
3) Are you able to see the whole Earth looking out the window of the space shuttle?
4) How do we know the Earth has layers?
5) What happens to the density of the Earth as you go toward the center?
6) Earth was a molten ball of rock when it formed. Why did some elements sink to the center?
Example:
Crust
Mantle
Outer core
Inner core