GEOL1340 EXAM 3 QUESTIONS SOLVED 100% LATEST VERSION 2025

GEOL1340 EXAM 3 QUESTIONS SOLVED 100% LATEST VERSION 2025 The figure below illustrates the motion of ____________ a. Surface waves b. S-waves c. P-waves d. Reflected waves - Answers P-Waves Circulation of liquid iron in the outer core is thought to be responsible for Earth's _____________ a. Gravity b. Geoid c. Magnetic field d. Rotation - Answers Magnetic field What is the main source of Earth's internal heat today? a. Radioactive decay of long-lived radioactive isotopes b. Meteorite impacts c. Gravitational contraction d. Solar radiation - Answers Radioactive decay of long-lived radioactive isotopes What happens to P- and S-waves when encountering transition zones at 400 km and 700 km depths? a. They slow down because mantle material is softened at these depths. b. P- and S-waves are reflected back to the surface. c. The two transition zones prevent P- and S-waves from reaching the lower mantle. d. They speed up due to density increases in mantle rock resulting from phase changes in minerals. - Answers They speed up due to density increases in mantle rock resulting from phase changes in minerals. Earth's overall density is calculated to be 5.52 grams per cubic centimeter. However, crustal rocks only give densities around 2.9 grams per cubic centimenter. Where is the excess density? a. The larger circumference of Earth at the equator relative to the poles means that the highest density occurs at zero degrees latitude b. Water stored in the oceans c. Iron in Earth's core d. Increasing pressures increase the density of mantle rocks at depth - Answers Iron in Earth's core The Moho is the boundary between the ________ and _________ a. Crust/upper mantle b. Mesosphere/outer core c. Outer core/inner core d. Asthenosphere/mesosphere - Answers Crust/upper mantle What changes in P- and S-waves occur when encountering the outer core that lead scientists to conclude that this layer is composed of liquid iron? a. P-waves slow down while S-waves speed up when passing through the outer core. b. Both P- and S-waves are prevented from passing through the outer core. c. S-waves cannot pass through the outer core while P-waves slow down significantly when passing through this layer. d. Both P- and S-waves increase in velocity when passing through the outer core. - Answers S-waves cannot pass through the outer core while P-waves slow down significantly when passing through this layer. The bending of seismic waves when passing through Earth's interior is due to changes in wave ____________ when encountering different Earth materials. a. Type b. Velocity c. Temperature d. Magnitude - Answers Velocity The bending of seismic waves when passing through Earth's interior is called _________ a. Reflection b. Diffraction c. Refraction d. Deflection - Answers Refraction The upper mantle is composed largely of an ultramafic rock called ___________ a. Peridotite b. Granite c. Basalt d. Andesite - Answers Peridotite What happens to S-waves as they pass through the asthenosphere? a. S-waves speed up because of an increase in density of mantle rocks b. S-waves change into P-waves c. S-waves cannot penetrate through the asthenosphere d. S-waves slow down because of the presence of a few percent partial melt - Answers Continental crust on average is _________ and ____________ than oceanic crust. a. Thinner/less dense b. Thinner/denser c. Thicker/denser d. Thicker/less dense - Answers Thicker/less dense What process led to the separation of Earth's hot interior into the core, mantle, and crust 4.5 billion years ago? a. Planetary differentiation b. Earth was struck by a Mars-sized object c. Outgassing of Earth's interior d. Radioactive decay of short-lived radioactive elements - Answers Planetary differentiation What happens when the velocity of seismic waves increases when passing from a shallower to deeper rock layer? a. Whe waves refract (bend upward) towards the boundary separating the layers b. The waves refract (bend downward) way from the boundary separating the layers c. The waves neither refract nor reflect but simply pass through the boundary without changing direction d. The waves always reflect off the boundary separating the layers - Answers Whe waves refract (bend upward) towards the boundary separating the layers What type of seismic wave travels the slowest and does the most damage during an earthquake? a. S-waves b. Surface waves c. Body waves d. P-waves - Answers Surface waves For the figure below, which letter corresponds to the epicenter of the earthquake? a. Site A b. Site B c. Site C d. Site D - Answers Site B P-wave shadow zones are regions on Earth's surface where... a. No P-waves are detected by seismometers. b. Only P-waves are detected by seismometers. c. S-waves change into P-waves. d. Only P-waves are generated by earthquakes. - Answers No P-waves are detected by seismometers. Which of the following statements about the D'' layer is FALSE? a. Occurs in the lower mantle near the boundary with the outer core b. Possible graveyard of subducted oceanic lithosphere c. Heat passes through the D'' layer mainly by radiation d. Birthplace of deep mantle plumes - Answers Heat passes through the D'' layer mainly by radiation Which of the following statements regarding heat flow on Earth is TRUE? a. Heat is generally transferred from Earth's surface down towards the core mainly by conduction. b.