GEOL 1121L Lab 2: Earth Interior Quiz Questions and Answers 100%
PASS- GSU
1. Which layer of the Earth is the thinnest?
A. Mantle
B. Crust
C. Outer Core
D. Inner Core
Answer: B
Rationale: The crust is the outermost and thinnest layer of the Earth, ranging from about 5
to 70 kilometers in thickness.
2. What is the primary composition of the Earth’s core?
A. Silicon and oxygen
B. Iron and nickel
C. Magnesium and iron
D. Aluminum and potassium
Answer: B
Rationale: The Earth’s core is primarily composed of an iron-nickel alloy, which accounts
for its high density.
3. Which seismic wave travels the fastest through the Earth’s interior?
A. S-waves
B. P-waves
C. Surface waves
D. Love waves
Answer: B
,Rationale: P-waves (Primary waves) are compressional waves and are the fastest seismic
waves, arriving first at recording stations.
4. What happens to the velocity of seismic waves as they move from the crust
into the mantle?
A. Velocity decreases
B. Velocity drops to zero
C. Velocity remains constant
D. Velocity increases
Answer: D
Rationale: Seismic wave velocity generally increases at the Moho boundary because the
mantle is denser and more rigid than the crust.
5. The lithosphere is composed of which two components?
A. Lower mantle and crust
B. Outer core and inner core
C. Mantle and outer core
D. Crust and upper mantle
Answer: D
Rationale: The lithosphere includes the crust and the uppermost, rigid part of the mantle.
6. Which layer is responsible for generating Earth’s magnetic field?
A. Inner Core
B. Asthenosphere
C. Outer Core
D. Mesosphere
Answer: C
Rationale: The movement of liquid iron and nickel in the outer core creates electric
currents that generate the magnetic field.
, 7. The ‘Moho’ is the boundary between which two layers?
A. Lithosphere and Asthenosphere
B. Mantle and Core
C. Crust and Mantle
D. Outer Core and Inner Core
Answer: C
Rationale: The Mohorovičić discontinuity (Moho) separates the crust from the underlying
mantle.
8. Why can S-waves not travel through the outer core?
A. The outer core is liquid
B. The outer core is too dense
C. The outer core is too cold
D. The outer core is solid
Answer: A
Rationale: S-waves (shear waves) cannot propagate through fluids because liquids do not
resist changes in shape (shear stress).
9. The asthenosphere is best described as being in what state?
A. Rigid solid
B. Completely liquid
C. Plastic or ductile solid
D. Gaseous
Answer: C
Rationale: The asthenosphere is a solid that can flow slowly over geological time, behaving
in a plastic or ductile manner.
PASS- GSU
1. Which layer of the Earth is the thinnest?
A. Mantle
B. Crust
C. Outer Core
D. Inner Core
Answer: B
Rationale: The crust is the outermost and thinnest layer of the Earth, ranging from about 5
to 70 kilometers in thickness.
2. What is the primary composition of the Earth’s core?
A. Silicon and oxygen
B. Iron and nickel
C. Magnesium and iron
D. Aluminum and potassium
Answer: B
Rationale: The Earth’s core is primarily composed of an iron-nickel alloy, which accounts
for its high density.
3. Which seismic wave travels the fastest through the Earth’s interior?
A. S-waves
B. P-waves
C. Surface waves
D. Love waves
Answer: B
,Rationale: P-waves (Primary waves) are compressional waves and are the fastest seismic
waves, arriving first at recording stations.
4. What happens to the velocity of seismic waves as they move from the crust
into the mantle?
A. Velocity decreases
B. Velocity drops to zero
C. Velocity remains constant
D. Velocity increases
Answer: D
Rationale: Seismic wave velocity generally increases at the Moho boundary because the
mantle is denser and more rigid than the crust.
5. The lithosphere is composed of which two components?
A. Lower mantle and crust
B. Outer core and inner core
C. Mantle and outer core
D. Crust and upper mantle
Answer: D
Rationale: The lithosphere includes the crust and the uppermost, rigid part of the mantle.
6. Which layer is responsible for generating Earth’s magnetic field?
A. Inner Core
B. Asthenosphere
C. Outer Core
D. Mesosphere
Answer: C
Rationale: The movement of liquid iron and nickel in the outer core creates electric
currents that generate the magnetic field.
, 7. The ‘Moho’ is the boundary between which two layers?
A. Lithosphere and Asthenosphere
B. Mantle and Core
C. Crust and Mantle
D. Outer Core and Inner Core
Answer: C
Rationale: The Mohorovičić discontinuity (Moho) separates the crust from the underlying
mantle.
8. Why can S-waves not travel through the outer core?
A. The outer core is liquid
B. The outer core is too dense
C. The outer core is too cold
D. The outer core is solid
Answer: A
Rationale: S-waves (shear waves) cannot propagate through fluids because liquids do not
resist changes in shape (shear stress).
9. The asthenosphere is best described as being in what state?
A. Rigid solid
B. Completely liquid
C. Plastic or ductile solid
D. Gaseous
Answer: C
Rationale: The asthenosphere is a solid that can flow slowly over geological time, behaving
in a plastic or ductile manner.
