Layers of the Earth Quiz
Questions: 16 · 10 minutes
1. A tectonic plate includes the crust and a rigid portion of the uppermost mantle. What mechanical layer is being described?
Asthenosphere
Outer core
Lithosphere
Lower mantle
2. Which sequence names Earth’s three main compositional layers from the surface toward the center?
Lithosphere, asthenosphere, mesosphere
Crust, mantle, core
Crust, asthenosphere, inner core
Mantle, crust, core
3. Seismic measurements place the crust-mantle boundary much deeper beneath a continent than beneath a nearby ocean basin. What best explains the difference?
Oceanic crust is generally thicker than continental crust
The mantle is absent beneath large continents
The outer core rises closer to the surface beneath oceans
Continental crust is generally thicker than oceanic crust
4. Seismologists observe that S-waves do not travel through part of Earth’s core. What conclusion does this evidence best support?
The inner core contains no metals
The mantle is entirely molten
The crust is denser than the core
The outer core is liquid
5. A dense oceanic plate bends downward at a deep-ocean trench and descends beneath another plate. Where does the descending lithosphere enter?
The inner core
The outer core
The continental crust
The mantle
6. Which ordering generally runs from the least dense to the most dense of Earth’s major compositional layers?
Mantle, crust, core
Core, mantle, crust
Crust, mantle, core
Crust, core, mantle
7. Tectonic plates can move over a hotter layer that remains mostly solid but deforms slowly over long periods. Which layer is this?
Asthenosphere
Inner core
Lithosphere
Continental crust
8. Which internal process contributes most directly to generating Earth’s global magnetic field?
Slow deformation of silicate rock in the mantle
Movement of electrically conductive liquid in the outer core
Rotation of rigid plates in the lithosphere
Melting of basalt beneath mid-ocean ridges
9. Why does Earth’s inner core remain solid even though its temperature is extremely high?
It receives no heat from surrounding layers
It is made mainly of low-melting silicate rock
It is protected from heat by the outer core
Immense pressure prevents its material from melting
10. A temperature probe could somehow travel from Earth’s surface toward its center. What broad trend should it record?
Temperature generally increases with depth
Temperature falls steadily toward the core
Temperature rises only while passing through the crust
Temperature remains nearly constant through every layer
11. A drilling project reaches farther below the surface than any previous borehole but extends only several kilometers. Which major compositional layer is it still within?
Crust
Mantle
Outer core
Inner core
12. A rock sample from newly formed seafloor is dark, dense, and rich in basalt. Which part of Earth does it most directly represent?
Lower mantle
Continental crust
Oceanic crust
Inner core
13. Which named boundary separates Earth’s crust from the mantle?
The Gutenberg discontinuity
The Lehmann discontinuity
The Mohorovičić discontinuity, or Moho
The asthenosphere
14. In a model of Earth’s mantle, hotter material slowly rises while cooler material sinks. Which process does the model represent?
Magnetic reversal
Mantle convection
Crustal weathering
Core crystallization
15. At a mid-ocean ridge, magma rises and cools to create new seafloor. The magma is primarily derived from material associated with which layer?
The inner core
The upper mantle
The continental crust
The outer core
16. A student groups the crust, mantle, and core by composition, then groups the lithosphere and asthenosphere separately. What property defines the second grouping?
Physical behavior and mechanical strength
Exact mineral composition alone
Age of the material
Distance from the equator