Chapter 11 HW

What is meant by elastic rebound? a. Elastic rebound refers to how the slippage along a fault (i.e., earthquake) allows the deformed rock to regain its original shape in a new location. b. Elastic rebound refers to how the slippage along a fault (i.e., earthquake) changes the shape of the two rock blocks but does not move them from their original positions. c. Elastic rebound refers to how the slippage along a fault (i.e., earthquake) allows the deformed rock to regain its original shape and location. d. Elastic rebound refers to how the slippage of a fault (i.e., earthquake) allows the deformed rock to return to its original location while retaining its new shape. e. Elastic rebound refers to how the slippage along a fault (i.e., earthquake) causes the rock involved to stay in its new shape in its new location.

a. Elastic rebound refers to how the slippage along a fault (i.e., earthquake) allows the deformed rock to regain its original shape in a new location.

Why does the wave height of a tsunami increase as the tsunami enters shallow water? a. In shallow water, the energy of the tsunami must be contained within a smaller water column. b. In shallow water, the energy of the tsunami must be contained within a larger water column. c. In shallow water, the wind driving the tsunami must push a smaller water column. d. In shallow water, the wind driving the tsunami must push a larger water column.

a. In shallow water, the energy of the tsunami must be contained within a smaller water column.

Why is the moment magnitude scale favored over the Richter scale for large earthquakes? a. The moment magnitude scale measures the total energy released, whereas the Richter scale only measures the amplitude of the largest seismic wave. b. The moment magnitude scale measures the amplitude of the largest seismic wave, whereas the Richter scale directly measures the total energy released by the earthquake. c. The moment magnitude scale measures the energy released from an earthquake, whereas the Richter scale only measures the amplitude of the earthquake's waves, which cannot be translated into the amount of energy released. d. The Richter has a tendency to overestimate the amount of energy released by an earthquake. e. The Richter scale cannot differentiate between the energy amounts released during very small earthquakes.

a. The moment magnitude scale measures the total energy released, whereas the Richter scale only measures the amplitude of the largest seismic wave.

What is a tsunami? a. a series of water waves that travel away from a fault in all directions at high speed b. a series of water waves that travel toward a fault in all directions at low speed c. a series of water waves that travel away from a fault in all directions at low speed d. a series of water waves that travel toward a fault in all directions at high speed

a. a series of water waves that travel away from a fault in all directions at high speed

What causes an earthquake such as the one that occurred in San Francisco in 1906? a. As volumes of magma beneath the lithosphere rise toward the surface, the sudden upward thrust causes an earthquake to occur. b. As plates move, stress builds up at the boundary. When the boundary eventually snaps, energy is released as an earthquake. c. When the two edges of a fault slowly glide past one another, an earthquake occurs. d. An abrupt change in the direction of plate motion causes an earthquake to occur (e.g. when a plate that is moving northward suddenly moves to the south).

b. As plates move, stress builds up at the boundary. When the boundary eventually snaps, energy is released as an earthquake.

Which ocean is associated with most tsunamis? a. Arctic Ocean b. Pacific Ocean c. Atlantic Ocean d. Indian Ocean

b. Pacific Ocean

Which of the following best describes how scientists help the public prepare for an earthquake event? a. Scientists can predict when earthquakes will happen and alert the public because there are many precursors and signs that an earthquake is about to occur. b. Scientists cannot predict when exactly an earthquake will occur, but they can identify tectonically active areas that are likely to produce earthquake activity and let the public know they are in an earthquake-prone area. c. Scientists have no idea what areas might experience earthquakes in the future, so there is no way to help the public prepare.

b. Scientists cannot predict when exactly an earthquake will occur, but they can identify tectonically active areas that are likely to produce earthquake activity and let the public know they are in an earthquake-prone area.

What characteristics do faults that experience fault creep exhibit? a. Fault creep may be considered safe and inactive. b Fault creep tends to produce numerous small to moderate earthquakes. c. Fault creep tends to produce slow, gradual displacements of rock blocks with little seismic shaking. d. Fault creep stores energy in the rocks for hundreds of years, one day unleashing a major earthquake. e. Fault creep tends to produce slow, gradual displacements of rock blocks with severe seismic shaking.

c. Fault creep tends to produce slow, gradual displacements of rock blocks with little seismic shaking.

The bend in the stone walls in the town of Hollister, California are a result of __________. a. ground subsidence due to compaction of unlithified sediments b. groundwater withdrawal from a former sag pond c. a fault creep along the Calaveras Fault d. a large earthquake that caused major loss of life and property damage e. extensive igneous activity whereby magma rose towards the surface, causing structural damage

c. a fault creep along the Calaveras Fault

What type of plate boundary are most tsunamis associated with? a. transform plate boundaries b. divergent plate boundaries c. convergent plate boundaries

c. convergent plate boundaries

What is liquefaction? a. shaking that results in fluid behavior of water-filled sediment b. movement of water into pore spaces during shaking of water-filled sediment c. fluid behavior of water-filled sediment during shaking

c. fluid behavior of water-filled sediment during shaking

What information is used to establish the lower numbers on the Modified Mercalli Intensity scale? a. if waves can be seen on the surface of the ground b. if objects are thrown upward c. how the earthquake is felt by people in an area d. how much damage is caused in an area by an earthquake e. if the ground cracks

c. how the earthquake is felt by people in an area

Which type of fault tends to produce the most destructive earthquakes? a. reverse fault b. strike-slip fault c. megathrust fault d. normal fault e. thrust fault

c. mega thrust fault

What type of interaction produces the San Andreas Fault? a. converging plates b. Diverging plates c. plates sliding past one another

c. plates sliding past one another

The offset of Wallace Creek is caused by __________. a. movement of the North American plate as it slides past the California plate in a northwest direction b. squeezing along the Big Bend over the past 2-4 million years c. right-lateral movement along the San Andreas strike-slip fault d. subduction of the Pacific plate under the North American Plate e. left lateral slip along the San Andreas normal fault

c. right-lateral movement along the San Andreas strike-slip fault

Which sediment below would have the highest cohesive strength during an earthquake? a. sediment with many contact points between grains and water in pore spaces b. sediment with few contact points between grains and water in pore spaces c. sediment with many contact points between grains and air in pore spaces d. sediment with few contact points and air in pore spaces

c. sediment with many contact points between grains and air in pore spaces

Which type(s) of seismic waves tend(s) to cause the greatest destruction to buildings? a. both surface and S waves b. P waves c. surface waves d. S waves e. both P and S waves

c. surface waves

How are tsunamis generated? a. through creation of the seafloor under water b. through displacement of the seafloor above water c. through displacement of the seafloor under water d. through creation of the seafloor above water

c. through displacement of the seafloor under water

Are accurate, short-range earthquake predictions currently possible using modern seismic instruments? a. Yes, animals often sense incoming processes in the natural world, and changes in their behavior can serve as precursors to earthquakes. b. Yes, changes in groundwater levels indicate that an earthquake will soon occur. c. Yes, earthquakes are always prefaced with an intense swarm or foreshocks, which warn residents in the area that an earthquake will soon occur. d. No, there are currently no reliable methods available for making short-range earthquake predictions. e. Yes, an earthquake has occurred every time that an area has been evacuated in its anticipation.

d. No, there are currently no reliable methods available for making short-range earthquake predictions.

What are the differences between P waves, S waves, and surface waves? a. Surface waves are the fastest and have the lowest amplitudes; S waves are the second-fastest and have the second-lowest amplitudes; P waves are the slowest and have the highest amplitudes. b. P waves are the fastest and have the highest amplitudes; S waves are the second-fastest and have the second-highest amplitudes; surface waves are the slowest and have the lowest amplitudes. c. S waves are the fastest and have the lowest amplitudes; P waves are the second-fastest and have the second-lowest amplitudes; surface waves are the slowest and have the highest amplitudes. d. P waves are the fastest and have the lowest amplitudes; S waves are the second-fastest and have the second-lowest amplitudes; surface waves are the slowest and have the highest amplitudes. e. Surface waves are the fastest and have the highest amplitudes; S waves are the second-fastest and have the second-highest amplitudes; P waves are the slowest and have the lowest amplitudes.

d. P waves are the fastest and have the lowest amplitudes; S waves are the second-fastest and have the second-lowest amplitudes; surface waves are the slowest and have the highest amplitudes.

Will Sumatra experience another tsunami like the destructive one of December 2004? a. This is unlikely, because Sumatra is near many ocean trenches. b. This is likely, because Sumatra is in the Pacific Ocean. c. This is unlikely, because Sumatra is in the Pacific Ocean. d. This is likely, because Sumatra is near many ocean trenches.

d. This is likely, because Sumatra is near many ocean trenches.

Why do ships at sea tend not to notice tsunamis? a. Tsunamis in deep water have large wave height and short wavelength. b. Tsunamis in deep water have large wave height and long wavelength. c. Tsunamis in deep water have small wave height and short wavelength. d. Tsunamis in deep water have small wave height and long wavelength.

d. Tsunamis in deep water have small wave height and long wavelength.

Earth's outer layer is composed of seven dominant plates. What is the name of this rigid outer layer? a. hydrosphere b. mantle c. asthenosphere d. lithosphere e. mesosphere

d. lithosphere

How does triangulation determine the epicenter of an earthquake? a. The distance from a recording center to a foreshock, the earthquake itself, and an aftershock are averaged together. A circle made with this radius is drawn around the record center; the epicenter is located within this circle. b. On a map, three lines are drawn to connect three stations that recorded the earthquake. The epicenter is known to be somewhere within this triangle. c. The distance from a recording center to a foreshock, the earthquake itself, and an aftershock are plotted against time on an XY graph. d. The time that it takes a P wave, an S wave, and a surface wave to reach a recording station are added together, and the average of these three times is calculated. This is done at three different recording stations; the station that has the lowest average of arrival time is closest to the epicenter of the earthquake. e. On a map, a circle is drawn around each of three recording stations, with the radius being the distance from the station to the epicenter of the earthquake. The epicenter is located where the three circles intersect.

e. On a map, a circle is drawn around each of three recording stations, with the radius being the distance from the station to the epicenter of the earthquake. The epicenter is located where the three circles intersect.

How are faults, hypocenters, and epicenters related? a. The hypocenter is the exact point underground along a fault where the slippage of the two blocks of rock occurs. The epicenter is the exact point along a fault at Earth's surface that is directly above the hypocenter. b. The epicenter is the exact point underground along a fault where the slippage of the two blocks of rock occurs. The hypocenter is the point on Earth's surface that is directly above the epicenter. c. The hypocenter is the exact point along a fault at Earth's surface where the slippage of the two blocks of rock occurs. The epicenter is the point under Earth's surface that is directly below the hypocenter. d. The epicenter is the exact point along a fault at Earth's surface where the slippage of the two blocks of rock occurs. The hypocenter is the point under Earth's surface that is directly below the epicenter. e. The hypocenter is the exact point underground along a fault where the slippage of the two blocks of rock occurs. The epicenter is the point on Earth's surface that is directly above the hypocenter.

e. The hypocenter is the exact point underground along a fault where the slippage of the two blocks of rock occurs. The epicenter is the point on Earth's surface that is directly above the hypocenter.

What is an earthquake, and how do earthquakes generally occur? a. a sudden shaking of the ground that is caused directly by convection within the mantle b. a sudden shaking of the ground that is caused by the impacts of falling rocks c. a sudden shaking of the ground that is caused by meteor impacts d. a sudden shaking of the ground that is caused by volcanoes erupting e. a sudden shaking of the ground that is caused by the rapid movement of one block of rock past another block of rock at a fault

e. a sudden shaking of the ground that is caused by the rapid movement of one block of rock past another block of rock at a fault

During an earthquake, _____. a. the entire length of a fault slips in an event that is sustained over a period of time b. the entire length of a fault slips in a series of events starting at the hypocenter and ending at both ends of the fault c. the slippage continues along the fault until it reaches a point where the type of rock is different d. the entire length of a fault slips in a single event that lasts less than 1 second e. the slippage continues along the fault until it reaches a point where rocks are not sufficiently strained to continue slippage

e. the slippage continues along the fault until it reaches a point where rocks are not sufficiently strained to continue slippage