Study Guide Lessons 2 and 3 Earth’s Structure with answers
Student Name _________________________
Test to be rescheduled for Friday, November 8
Lesson 2 Earth’s Interior
1. How do scientists gather evidence about the composition of Earth’s interior?
Scientists analyze earthquake waves to understand the composition of Earth’s
interior. Some seismic waves can go through some materials and not others.
2. How do scientists use earthquake waves to study Earth’s interior?
Scientists can study the three types of waves released by earthquakes. The three
types of earthquake waves are P waves, S waves, and L, or surface waves.
Scientists can study the three types of waves released by earthquakes. The three
types of earthquake waves are P waves, S waves, and L, or surface waves. Some
earthquake waves cannot travel through solid materials. Others can and others
travel at different rates of speed through plastic material or solid material. By
looking at how the waves travel through the earth, seismologists can determine
what kind of material is being traveled through.
3. What kinds of materials might stop a wave or make it change direction?
Some waves are not able to travel through a liquid, such as the liquid outer core
Some waves might change direction if they change from a liquid to a solid or
from a solid to a liquid. Inside this earth this would be indicated as movement
from the liquid to a solid or a solid to a liquid.
4. How does oceanic crust differ from continental crust?
Oceanic crust is denser and much thinner than continental crust. It also
contains heavier elements such as iron and magnesium.
5. Which elements make up continental crust?i
Continental crust is made up of silicon and oxygen.
6. How is the crust different from the mantle?
The mantle has more iron and magnesium than the crust does. The crust is
above the mantle, and is less dense than the mantle.
7. Compare the lithosphere and the asthenosphere.
The lithosphere is a rigid layer and the asthenosphere is a plastic layer. The
lithosphere contains both the crust and the uppermost mantle. The
asthenosphere is part of the mantle. The asthenosphere is the innermost (lower
mantle) layer of the mantle. It is composed of molten bits of rock that are able
to flow. The term used for “able to flow” is plastic.
8. What are the four layers of the mantle?
The four layers of the mantle are the uppermost mantle (nearest the crust of the
earth), the asthenosphere, the upper and the lower mantle(located beneath the
asthenosphere.)
9. Which layer of the mantle has the highest pressure?
The lower mantle has the highest pressure. Pressure increases as the layers get
further away from the surface of the earth.
10. What are two ways that you can change melted rock to a solid?
You can change melted rock to a solid by increasing pressure or by decreasing
temperature.
11. What are the innermost layers of the earth?
The inner most layers of the earth are the inner core and the outer core.
12. Which part of the mantle is also part of the lithosphere?
The lithosphere is composed of the crust and the upper mantle.
13. What element makes up the inner core?
The inner core is composed of solid iron crystals. The outer core is composed
of iron and nickel.
14. If the inner core is under greater pressure than the outer core, how is the outer core
liquid and the inner core is solid?
The inner core is composed of iron which has a higher melting point than
nickel which is found in the outer core. For this reason, the nickel in the outer
core melts and flows while the iron in the inner core, which is also under
greater pressure remains a layer of solid iron crystals.
15.
What evidence is used to determine that the outer core is liquid?
Earthquake waves.
16. What causes the formation of the magnetic field around the earth?
The inner core spins faster than the outer core. This causes the formation of
the magnetic field. The outermost part of the magnetic field is called the
magnetosphere.
17. What is a landform?
A landform is a topographic feature formed by earth-forming processes.
Landforms are not permanent. They may change over time as earth goes
through other earth forming processes such as volcanism, erosion, and
weathering.
18.
List and describe three kinds of landforms.
Three kinds of landforms are plains, plateaus, and mountains. Plains are
landforms, or geographic regions, that have low relief, which means they are
relatively flat, and low elevation. Plateaus are landforms that have steep sides
and flat tops, which means that they have high elevation and low relief.
Mountains are landforms that have both high elevation and high relief.
19.
What type of landforms might you find in Louisiana?
Deltas, beaches, islands, peninsulas, estuaries, marshes.
20. What is the highest landform in Louisiana and where is it located?
Driskill Mountain in Bienville Parish.