G202 EXAM 2: GEOLOGY, PLATE
TECTONICS, AND GEOLOGIC
STRUCTURES QUESTIONS AND
ANSWERS 100% VERIFIED. JUST
RELEASED
1. Which of the following best describes the Wadati-Benioff zone?
A. A planar zone of seismicity corresponding with the down-going slab in a subduction
zone.
B. A region of high heat flow located directly beneath mid-ocean ridges.
C. The boundary layer between the outer core and the lower mantle.
D. A zone of plastic deformation where rocks fold rather than fracture.
Answer: A
Conceptual Explanation: The Wadati-Benioff zone is a site of frequent earthquakes that
traces the position of a subducting oceanic plate as it descends into the mantle.
2. Which factor is primarily responsible for the low viscosity of basaltic magma compared to
rhyolitic magma?
A. Higher gas content.
B. Higher crystal content.
,C. Increased pressure at depth.
D. Lower silica content and higher temperature.
Answer: D
Conceptual Explanation: Silica tetrahedra tend to link together; lower silica content
means fewer chains, and higher temperatures increase kinetic energy, both reducing
viscosity.
3. In a reverse fault, how does the hanging wall move relative to the footwall?
A. Upwards.
B. Horizontally to the left.
C. Downwards.
D. Horizontally to the right.
Answer: A
Conceptual Explanation: Reverse faults are caused by compressional stress, forcing the
hanging wall up and over the footwall.
4. Which seismic wave travels the fastest and arrives first at a recording station?
A. S-waves
B. P-waves
C. Rayleigh waves
, D. Love waves
Answer: B
Conceptual Explanation: P-waves (Primary waves) are compressional waves and are the
fastest seismic waves.
5. The ‘Moment Magnitude’ scale (Mw) is considered more accurate than the Richter scale for
large earthquakes because it measures:
A. The amplitude of the largest surface wave.
B. The level of perceived shaking by humans.
C. The total energy released based on fault rupture area and slip amount.
D. The duration of the S-P interval.
Answer: C
Conceptual Explanation: Moment magnitude accounts for the physical properties of the
fault, including the area of the rupture and the amount of displacement.
6. A volcanic crater that exceeds 1 kilometer in diameter, usually formed by the collapse of
the magma chamber, is called a:
A. Fissure
B. Vent
C. Cinder cone
D. Caldera
TECTONICS, AND GEOLOGIC
STRUCTURES QUESTIONS AND
ANSWERS 100% VERIFIED. JUST
RELEASED
1. Which of the following best describes the Wadati-Benioff zone?
A. A planar zone of seismicity corresponding with the down-going slab in a subduction
zone.
B. A region of high heat flow located directly beneath mid-ocean ridges.
C. The boundary layer between the outer core and the lower mantle.
D. A zone of plastic deformation where rocks fold rather than fracture.
Answer: A
Conceptual Explanation: The Wadati-Benioff zone is a site of frequent earthquakes that
traces the position of a subducting oceanic plate as it descends into the mantle.
2. Which factor is primarily responsible for the low viscosity of basaltic magma compared to
rhyolitic magma?
A. Higher gas content.
B. Higher crystal content.
,C. Increased pressure at depth.
D. Lower silica content and higher temperature.
Answer: D
Conceptual Explanation: Silica tetrahedra tend to link together; lower silica content
means fewer chains, and higher temperatures increase kinetic energy, both reducing
viscosity.
3. In a reverse fault, how does the hanging wall move relative to the footwall?
A. Upwards.
B. Horizontally to the left.
C. Downwards.
D. Horizontally to the right.
Answer: A
Conceptual Explanation: Reverse faults are caused by compressional stress, forcing the
hanging wall up and over the footwall.
4. Which seismic wave travels the fastest and arrives first at a recording station?
A. S-waves
B. P-waves
C. Rayleigh waves
, D. Love waves
Answer: B
Conceptual Explanation: P-waves (Primary waves) are compressional waves and are the
fastest seismic waves.
5. The ‘Moment Magnitude’ scale (Mw) is considered more accurate than the Richter scale for
large earthquakes because it measures:
A. The amplitude of the largest surface wave.
B. The level of perceived shaking by humans.
C. The total energy released based on fault rupture area and slip amount.
D. The duration of the S-P interval.
Answer: C
Conceptual Explanation: Moment magnitude accounts for the physical properties of the
fault, including the area of the rupture and the amount of displacement.
6. A volcanic crater that exceeds 1 kilometer in diameter, usually formed by the collapse of
the magma chamber, is called a:
A. Fissure
B. Vent
C. Cinder cone
D. Caldera
