Answer Key Earth’s Layers Study Guide
1. Which layer of the Earth’s interior has the most volume? mantle
2. Describe the crust. The rigid, outermost layer of the Earth
3. What makes up the lithosphere? The crust and upper mantle
4. Which layer of the Earth do the tectonic plates move on top of? The asthenosphere (the
middle mantle
5. Which two metals are the inner and outer core mostly made of? Iron and nickel
6. How is the outer core of Earth different from the inner core? the inner core is solid while
the outer core is liquid
7. Scientists study different parts of earthquakes and
how they are related. This illustration shows a cross
section of the lithosphere when an earthquake is
taking place. Where would the strongest effects of
this earthquake be felt? What is the term for this
location? What is happening at point “A”?
Earthquake would be strongest at point B which is the epicenter. Point A is the focus.
8. How does energy travel through Earth’s crust after an earthquake? Through the crust as
seismic waves
9. A tsunami is massive wave that can cause a tremendous amount of damage to land
masses. What causes a tsunami? An earthquake on the ocean floor.
10.What causes an earthquake? The sudden release of accumulated strain at a plate
boundary
11.Complete the table below comparing the oceanic and continental crust.
Feature
Location
Main
elements
Density
Thickness
Oceanic crust
Beneath the ocean
and under continental
crust
oxygen, silicon,
aluminum
Higher density than
continental crust
Thinner than
continental crust
Continental crust
Continental land masses
oxygen, silicon, aluminum
Lower density than
oceanic crust
Thicker than oceanic
crust
12.What is the relationship between the lithosphere and the asthenosphere? The lithosphere
floats on top of the asthenosphere and convection currents in the asthenosphere move the
lithosphere across Earth’s surface.
13.Which of earth's spheres is best represented by the following diagram? geosphere
1
2
3
4
14.Think back to the lesson on the fundamental force of nature. What is one of the possible
reasons that the core of the Earth is so hot? Weak nuclear force – radioactive decay
occurring in the core
15.Describe the asthenosphere. Slow moving, hot, plastic like liquid rock located under the
lithosphere
16.What do geologists believe is the source of the Earth’s magnetic field? The slow flowing
of the iron and nickel in the Earth’s outer core
17.How do scientists know what Earth’s interior looks like? Studying seismic waves as they
travel through the Earth
18.What is the difference between compression and rarefaction? Compression is the
squeezing together of the wavelengths while
rarefaction refers to it spreading out.
Use the diagram of the wave below to answer
questions 19 and 20.
19.What type of wave is diagrammed above? transverse
20.What do the labeled parts represent?
S – crest
T – amplitude
W – wavelength
X – trough