Eas 2600 - 2
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Questions and Answers
- 1.
In response to deformation brittle materials will _____ whereas ductile materials will ____.
- A.
Expand; shrink
- B.
Fold; fault
- C.
Fault; fold
- D.
Flow; fracture
Correct Answer
C. Fault; foldExplanation
When brittle materials undergo deformation, they tend to break or fracture rather than undergo plastic deformation. This is why they are more likely to form faults, where there is a fracture or displacement along a fault line. On the other hand, ductile materials have the ability to undergo plastic deformation, which means they can be bent or stretched without breaking. As a result, they are more likely to form folds, where layers of rock are bent and deformed without breaking.Rate this question:
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- 2.
The moment magnitude of an earthquake is proportional to
- A.
The area of the fault break
- B.
The seismic energy released during the rupture
- C.
The area of the fault break and the seismic energy released during the rupture
- D.
Neither the area of the fault break nor the seismic energy released during the rupture
Correct Answer
C. The area of the fault break and the seismic energy released during the ruptureExplanation
The moment magnitude of an earthquake is determined by both the area of the fault break and the seismic energy released during the rupture. This means that the larger the area of the fault break and the greater the amount of energy released, the higher the moment magnitude of the earthquake. Therefore, both factors contribute to the overall strength and intensity of the earthquake.Rate this question:
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- 3.
Which of the following statements about the metamorphism of a shale is false?
- A.
With increasing metamorphism, clay minerals break down to form micas
- B.
With increasing metamorphism, the grain size of the rock gets smaller
- C.
With increasing metamorphism, foliation develops
- D.
With increasing metamorphism, the amount of water in the rock decreases
Correct Answer
B. With increasing metamorphism, the grain size of the rock gets smallerExplanation
The statement that with increasing metamorphism, the grain size of the rock gets smaller is true. During metamorphism, the intense heat and pressure cause recrystallization of minerals, resulting in smaller grain sizes. This process is known as neocrystallization. As the rock undergoes further metamorphism, the grains continue to recrystallize and become even smaller in size. This is a common characteristic of metamorphic rocks and is observed in various types of rocks, including shales.Rate this question:
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- 4.
An oblique-slip fault suggests
- A.
Compressive forces only
- B.
Shear forces only
- C.
Tensional forces only
- D.
Shear forces combined with compressive or tensional forces
Correct Answer
D. Shear forces combined with compressive or tensional forcesExplanation
An oblique-slip fault suggests shear forces combined with compressive or tensional forces. This type of fault occurs when there is both horizontal and vertical movement along the fault plane. The shear forces cause the rocks on either side of the fault to slide past each other horizontally, while the compressive or tensional forces cause the rocks to move vertically. This combination of forces is characteristic of oblique-slip faults.Rate this question:
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- 5.
Abrasion of sediment particles results in which of the following?
- A.
They become smaller and more angular
- B.
They become smaller and more rounded
- C.
They become larger and heavier
- D.
They become larger and more angular
Correct Answer
B. They become smaller and more roundedExplanation
When sediment particles undergo abrasion, they experience friction and rubbing against each other, causing them to break down into smaller fragments. Additionally, the constant grinding action smoothens the edges and corners of the particles, resulting in a more rounded shape. Therefore, the correct answer is that sediment particles become smaller and more rounded due to abrasion.Rate this question:
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- 6.
Different pressure-temperature zones within a belt of regionally metamorphosed rock are defined by the presence of _______.
- A.
Porphyroblasts
- B.
Index minerals
- C.
Migmatite
- D.
Sillimanite
Correct Answer
B. Index mineralsExplanation
Different pressure-temperature zones within a belt of regionally metamorphosed rock are defined by the presence of index minerals. Index minerals are specific minerals that form under certain pressure and temperature conditions during metamorphism. They act as indicators of the metamorphic grade, helping geologists determine the intensity of the metamorphic process that occurred in a specific area. By identifying the presence of index minerals, geologists can classify the rock into different metamorphic zones and understand the geological history of the region.Rate this question:
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- 7.
What process generates Earth's magnetic field?
- A.
Earth's rotation
- B.
The magnetic stripes on the seafloor when it moves
- C.
Flow in the outer core
- D.
Movement of the continents that drag the magnetic poles with it
Correct Answer
C. Flow in the outer coreExplanation
The flow in the outer core generates Earth's magnetic field. The outer core is composed of molten iron and nickel, and the movement of this liquid metal creates electric currents. These electric currents, in turn, generate a magnetic field. This process is known as the dynamo effect and is responsible for Earth's magnetic field.Rate this question:
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- 8.
Which of the following processes is responsible for the recording of the magnetic reversals on the seafloor?
- A.
Depositional remanent magnetism
- B.
Tectonosilicate magnetism
- C.
Metamorphic magnetism
- D.
Thermoremanent magnetism
Correct Answer
D. Thermoremanent magnetismExplanation
Thermoremanent magnetism is the process responsible for the recording of magnetic reversals on the seafloor. This process occurs when molten rock cools and solidifies, locking in the orientation of the Earth's magnetic field at that time. As the seafloor spreads and new rock is formed, the magnetic minerals align with the current magnetic field direction. Over time, the Earth's magnetic field reverses, and these reversals are recorded in the magnetic orientation of the seafloor rocks.Rate this question:
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- 9.
An earthquake's Richter magnitude is based on the
- A.
Amount of energy released during an earthquake
- B.
Amount of ground movement caused by seismic waves
- C.
Distance between the earthquake and the seismograph station
- D.
Observed effects on people and structures
Correct Answer
B. Amount of ground movement caused by seismic wavesExplanation
The Richter magnitude of an earthquake is determined by the amount of ground movement caused by seismic waves. This measurement is based on the amplitude of the seismic waves recorded on a seismograph. The greater the ground movement, the higher the Richter magnitude, indicating a more powerful earthquake. This measurement is important in assessing the strength and potential impact of an earthquake.Rate this question:
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- 10.
The line formed by the intersection of an inclined sedimentary layer and a horizontal plane is called the ______.
- A.
Bed
- B.
Dip
- C.
Fold axis
- D.
Strike
Correct Answer
D. StrikeExplanation
The line formed by the intersection of an inclined sedimentary layer and a horizontal plane is called the "strike." The strike represents the direction of the horizontal line on the inclined layer. It is a fundamental concept in structural geology and is used to determine the orientation and direction of geological features such as folds, faults, and rock layers. By understanding the strike, geologists can interpret the geological history and structure of an area.Rate this question:
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- 11.
Analysis of fault mechanisms indicates ___________ at divergent boundaries and _______ at transform boundaries.
- A.
Compression; tension
- B.
Shear; compression
- C.
Tension; shear
- D.
Shear; tension
Correct Answer
C. Tension; shearExplanation
The correct answer is tension; shear. This is because at divergent boundaries, where two plates are moving apart, tension forces are generated, causing the plates to separate. On the other hand, at transform boundaries, where two plates are sliding past each other horizontally, shear forces are generated, causing the plates to slide past each other.Rate this question:
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- 12.
What is the most abundant nonclastic sediment?
- A.
Carbonate
- B.
Chert
- C.
Coal
- D.
Halite
Correct Answer
A. CarbonateExplanation
Carbonate is the most abundant nonclastic sediment because it is formed from the accumulation of shells and skeletons of marine organisms such as coral, mollusks, and foraminifera. These organisms extract calcium carbonate from the water to build their shells, and when they die, their remains settle on the ocean floor. Over time, these accumulated remains form limestone, which is a type of carbonate sediment. Limestone is widespread and can be found in various forms such as chalk, marble, and dolomite. Therefore, carbonate is the correct answer as it is the most common nonclastic sediment.Rate this question:
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- 13.
How fast do tsunamis travel across the ocean?
- A.
Up to 5 kilometers per hour
- B.
Up to 60 kilometers per hour
- C.
Up to 800 kilometers per hour
- D.
Up to 10,000 kilometers per hour
Correct Answer
C. Up to 800 kilometers per hourExplanation
Tsunamis can travel at speeds of up to 800 kilometers per hour across the ocean. This is due to the immense amount of energy they carry, which allows them to propagate quickly and cover large distances. The speed at which a tsunami travels depends on various factors, including the depth of the water and the distance from the earthquake or underwater disturbance that triggered it. While tsunamis may slow down as they approach shallow waters near the coastline, their initial speed in the open ocean can be incredibly fast.Rate this question:
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- 14.
Which of the following types of tectonic forces tends to push two sides of a body in opposite directions so that they slide horizontally past each other?
- A.
Compressive forces
- B.
Tensional forces
- C.
Shearing forces
- D.
Torsional forces
Correct Answer
C. Shearing forcesExplanation
Shearing forces are the type of tectonic forces that tend to push two sides of a body in opposite directions so that they slide horizontally past each other. These forces occur when rocks are subjected to lateral stress, causing them to deform and slide along a fault plane. Shearing forces are responsible for the formation of transform boundaries, where two tectonic plates slide past each other horizontally, leading to earthquakes and the creation of features such as strike-slip faults.Rate this question:
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- 15.
Which mineral is commonly used to determine a metamorphic P-T path?
- A.
Calcite
- B.
Garnet
- C.
Muscovite
- D.
Quartz
Correct Answer
B. GarnetExplanation
Garnet is commonly used to determine a metamorphic P-T path because it is a mineral that forms under specific temperature and pressure conditions. The composition and zoning patterns of garnet can provide valuable information about the conditions that the rock has experienced during its metamorphic history. By analyzing the size, shape, and composition of garnet crystals, geologists can infer the temperature and pressure conditions that the rock has been subjected to, helping to determine the metamorphic path it has followed.Rate this question:
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- 16.
Sedimentary basins are formed by a process called
- A.
Diagenesis
- B.
Subduction
- C.
Subsidence
- D.
Lithification
Correct Answer
C. SubsidenceExplanation
Sedimentary basins are formed through the process of subsidence. Subsidence refers to the sinking or downward movement of the Earth's crust, which creates a depression or basin. This downward movement can be caused by various factors such as tectonic activity, the weight of sediment accumulation, or the cooling and contraction of the Earth's crust. As the crust sinks, it creates a space for sediments to accumulate and eventually form sedimentary rocks. Therefore, subsidence plays a crucial role in the formation of sedimentary basins.Rate this question:
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- 17.
The modified Mercalli intensity scale measures the
- A.
Amount of destruction caused by an earthquake
- B.
Amount of slip on a fault plane caused by an earthquake
- C.
Amplitude of the surface waves
- D.
Type of seismic wave in an earthquake
Correct Answer
A. Amount of destruction caused by an earthquakeExplanation
The modified Mercalli intensity scale measures the amount of destruction caused by an earthquake. This scale is used to assess the impact of an earthquake by considering the observed effects on structures, human-made objects, and the environment. It takes into account factors such as building damage, ground shaking, and the overall impact on communities and infrastructure. The scale provides a qualitative assessment of the earthquake's intensity, ranging from I (not felt) to XII (total destruction). By measuring the amount of destruction, the scale helps in understanding the severity and impact of an earthquake on a local scale.Rate this question:
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- 18.
The P wave shadow extends from roughly ___ to roughly ____ distance from an earthquake's focus.
- A.
60°; 100°
- B.
100°; 140°
- C.
140°; 180°
- D.
180°; 220°
Correct Answer
B. 100°; 140°Explanation
The P wave shadow refers to the area on the Earth's surface where P waves from an earthquake are not detected. This is because the P waves are refracted or absorbed by the Earth's core. The given answer of 100° to 140° suggests that the P wave shadow extends from approximately 100° to 140° away from the earthquake's focus.Rate this question:
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- 19.
Which of the following statements is FALSE?
- A.
S waves slow down as they travel through the mantle.
- B.
P waves slow down in the outer core.
- C.
S waves cannot transmit through the outer core.
- D.
P waves travel through the inner core.
Correct Answer
A. S waves slow down as they travel through the mantle.Explanation
The given statement that S waves slow down as they travel through the mantle is false. In reality, S waves cannot pass through the Earth's liquid outer core, so they abruptly stop at the core-mantle boundary. However, P waves do slow down as they travel through the mantle, due to the increased density of the rock layers. P waves can also travel through the solid inner core, but they experience a slight increase in speed as they pass through it.Rate this question:
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- 20.
Where, inside Earth, is the largest change in material density?
- A.
Base of the crust
- B.
Base of the lithosphere
- C.
Core-mantle boundary
- D.
Outer core-inner core boundary
Correct Answer
C. Core-mantle boundaryExplanation
The largest change in material density inside Earth occurs at the core-mantle boundary. This boundary marks the transition between the Earth's liquid outer core and the solid mantle. The outer core is primarily composed of molten iron and nickel, while the mantle is made up of solid rock. This stark contrast in material composition leads to a significant change in density at this boundary.Rate this question:
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- 21.
What kind of metamorphism would you expect to be pervasive on the lunar surface?
- A.
Regional metamorphism
- B.
Burial metamorphism
- C.
Contact metamorphism
- D.
Shock metamorphism
Correct Answer
D. Shock metamorphismExplanation
Shock metamorphism would be the most pervasive kind of metamorphism on the lunar surface due to the frequent impact events that occur on the moon. These impact events create high-pressure and high-temperature conditions, causing rapid and intense changes in the rocks. This type of metamorphism is characterized by the formation of shock features such as shatter cones, melt rocks, and high-pressure minerals. The moon's lack of an atmosphere and tectonic activity further supports the dominance of shock metamorphism as the primary metamorphic process on its surface.Rate this question:
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- 22.
When the axial plane of a fold is tilted beyond the vertical, it's called a(n) _____ fold.
- A.
Nonvertical
- B.
Horizontal
- C.
Plunging
- D.
Overturned
Correct Answer
D. OverturnedExplanation
When the axial plane of a fold is tilted beyond the vertical, it is called an overturned fold. This means that the fold has been tilted to the point where the limbs of the fold are completely upside down, with the older rocks on top and the younger rocks on the bottom. This type of fold is often caused by intense tectonic forces that have pushed the rock layers to extreme angles.Rate this question:
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- 23.
At what temperature does organic matter begin to convert to oil and gas?
- A.
90°C
- B.
50°C
- C.
190°C
- D.
150°C
Correct Answer
A. 90°CExplanation
Organic matter begins to convert to oil and gas at a temperature of 90°C. This is the temperature at which the process of thermal decomposition, also known as pyrolysis, occurs. During pyrolysis, the organic matter is heated and breaks down into hydrocarbons, which are the main components of oil and gas. Therefore, 90°C is the critical temperature at which the conversion of organic matter into oil and gas begins.Rate this question:
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- 24.
Which of the following is a general pressure in all directions, such as the pressure that the atmosphere exerts?
- A.
Confining pressure
- B.
Pore pressure
- C.
Directional pressure
- D.
Stress pressure
Correct Answer
A. Confining pressureExplanation
Confining pressure is the correct answer because it refers to the pressure that is exerted uniformly in all directions, just like the pressure exerted by the atmosphere. This type of pressure occurs when a material is subjected to external forces that compress it equally from all sides. It is commonly seen in geological formations where rocks or fluids are confined by surrounding materials, such as in underground reservoirs or deep within the Earth's crust.Rate this question:
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- 25.
A seismic observatory typically has instruments that measure ______ motion(s).
- A.
Up-down
- B.
Horizontal north-south
- C.
Horizontal east-west
- D.
Up-down, horizontal north-south, and horizontal east-west
Correct Answer
D. Up-down, horizontal north-south, and horizontal east-westExplanation
A seismic observatory typically has instruments that measure up-down, horizontal north-south, and horizontal east-west motion. This is because earthquakes can cause motion in all three directions, and it is important to measure and record these motions accurately in order to study and understand seismic activity. By measuring motion in all three directions, scientists can gather comprehensive data on the intensity, duration, and direction of seismic events, which can help in predicting future earthquakes and assessing their potential impact.Rate this question:
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- 26.
Which of the following metamorphic rocks cannot form from a shale?
- A.
Hornfels
- B.
Marble
- C.
Schist
- D.
Slate
Correct Answer
B. MarbleExplanation
Marble is a metamorphic rock that forms from limestone or dolomite, not shale. Shale is a sedimentary rock composed of clay minerals, while marble forms from the metamorphism of carbonate rocks. The high temperatures and pressures required for the formation of marble are not typically found in the metamorphic process of shale. Therefore, marble cannot form directly from shale.Rate this question:
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- 27.
The ground motion during a Richter magnitude 8 earthquake is ______ times greater than the ground motion during a Richter magnitude 6 earthquake.
- A.
2
- B.
10
- C.
100
- D.
1000
Correct Answer
C. 100Explanation
During an earthquake, the Richter magnitude scale is used to measure the intensity of the ground motion. Each increase of 1 on the Richter scale represents a tenfold increase in the amplitude of the ground motion and approximately 31.6 times more energy released. Therefore, the ground motion during a Richter magnitude 8 earthquake is 100 times greater than the ground motion during a Richter magnitude 6 earthquake.Rate this question:
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- 28.
The prograde part of a metamorphic P-T path occurs during __________.
- A.
Burial and cooling
- B.
Exhumation and cooling
- C.
Burial and heating
- D.
Exhumation and heating
Correct Answer
C. Burial and heatingExplanation
The prograde part of a metamorphic P-T path occurs during burial and heating. This means that as rocks are buried deeper in the Earth's crust, they experience an increase in temperature, which causes metamorphic changes to occur. This increase in temperature and pressure leads to the formation of new minerals and the recrystallization of existing minerals, resulting in the transformation of the rock.Rate this question:
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- 29.
How thick is the oceanic crust?
- A.
7 km
- B.
70 km
- C.
35 km
- D.
240 km
Correct Answer
A. 7 kmExplanation
The oceanic crust is relatively thin compared to the continental crust. It has an average thickness of about 7 km. This is because the oceanic crust is constantly being created at mid-ocean ridges through volcanic activity, and then being consumed at subduction zones. This continuous process of creation and destruction results in a thinner crust compared to the continental crust, which is much older and has not undergone the same level of recycling.Rate this question:
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- 30.
How many seismograph stations are needed to locate the epicenter of an earthquake?
- A.
Three
- B.
One
- C.
Two
- D.
Four
Correct Answer
A. ThreeExplanation
To accurately locate the epicenter of an earthquake, at least three seismograph stations are needed. This is because seismic waves travel at different speeds and angles through the Earth's layers. By analyzing the time difference between the arrival of these waves at different stations, scientists can triangulate the epicenter. With only one or two stations, it would be difficult to determine the exact location, but with three or more, the intersection of the circles drawn around each station can pinpoint the epicenter. Therefore, three seismograph stations are necessary for precise earthquake epicenter location.Rate this question:
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- 31.
Which of the following statements regarding aftershocks is TRUE?
- A.
The number and sizes of aftershocks both increase with time.
- B.
The number of aftershocks increases with time, while the sizes of aftershocks decrease with time.
- C.
The number and sizes of aftershocks both decrease with time.
- D.
The number of aftershocks decreases with time, while the sizes of aftershocks increase with time.
Correct Answer
C. The number and sizes of aftershocks both decrease with time.Explanation
The correct answer is that the number and sizes of aftershocks both decrease with time. This means that after a main earthquake, the frequency and intensity of aftershocks gradually decrease over time. As the stress in the Earth's crust is released, there are fewer and smaller aftershocks. This is a common pattern observed in seismic activity following a major earthquake.Rate this question:
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- 32.
Seismic tomography has revealed that seismic waves in the uppermost mantle are relatively
- A.
Slow beneath mid-ocean ridges and fast beneath subduction zones.
- B.
Fast beneath both mid-ocean ridges and subduction zones.
- C.
Slow beneath both mid-ocean ridges and subduction zones.
- D.
Fast beneath mid-ocean ridges and slow beneath subduction zones.
Correct Answer
A. Slow beneath mid-ocean ridges and fast beneath subduction zones.Explanation
Seismic tomography is a technique used to study the Earth's interior by analyzing seismic waves. This technique has shown that seismic waves in the uppermost mantle, which is the layer just below the Earth's crust, have different velocities in different regions. The statement in the answer suggests that seismic waves are slower beneath mid-ocean ridges and faster beneath subduction zones. This is consistent with the geological processes that occur in these regions. Mid-ocean ridges are areas where tectonic plates are moving apart, causing the mantle to rise and cool, which leads to slower seismic waves. On the other hand, subduction zones are areas where one tectonic plate is being forced beneath another, creating intense pressure and heat, which results in faster seismic waves.Rate this question:
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- 33.
The average time between large earthquake events along a fault is known as the ______ interval.
- A.
Recurrence
- B.
Fault slip
- C.
Seismic
- D.
Hazard
Correct Answer
A. RecurrenceExplanation
The average time between large earthquake events along a fault is known as the recurrence interval. This term refers to the period of time that typically elapses between successive earthquakes of similar magnitude along a specific fault. It helps scientists and seismologists to estimate the probability of future earthquakes and assess the level of seismic hazard in a particular region. By studying the recurrence intervals, researchers can gain insights into the behavior and patterns of seismic activity along faults.Rate this question:
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- 34.
What type of metamorphism is caused by igneous intrusions?
- A.
Contact metamorphism
- B.
Burial metamorphism
- C.
Shock metamorphism
- D.
Regional metamorphism
Correct Answer
A. Contact metamorphismExplanation
Igneous intrusions can cause contact metamorphism, which refers to the changes in rocks that occur when they come into contact with a hot magma body. The heat from the magma alters the surrounding rocks, causing them to recrystallize and form new minerals. This type of metamorphism typically occurs in the vicinity of the intrusion and is characterized by a distinct zone of altered rocks known as a contact aureole. It is different from regional metamorphism, which is caused by large-scale tectonic forces, burial metamorphism, which occurs due to the pressure from overlying sediments, and shock metamorphism, which results from the intense pressure and heat generated by meteorite impacts.Rate this question:
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- 35.
Which of the following statements about the Mohorovičić discontinuity (Moho) is FALSE?
- A.
The speed of seismic waves increases as they pass down through the Moho.
- B.
The Moho separates the crust from the mantle.
- C.
The Moho marks the top of a partially molten layer.
- D.
The Moho separates denser rocks below from less dense rocks above.
Correct Answer
C. The Moho marks the top of a partially molten layer.Explanation
The Mohorovičić discontinuity (Moho) is a boundary that separates the crust from the mantle. It is characterized by a change in seismic wave velocities, with the speed of seismic waves increasing as they pass down through the Moho. The Moho does not mark the top of a partially molten layer, as there is no evidence to suggest that it is associated with molten material. Instead, it separates denser rocks below from less dense rocks above.Rate this question:
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- 36.
The size of an earthquake can be related to fault
- A.
Rupture area.
- B.
Width.
- C.
Type.
- D.
Length.
Correct Answer
A. Rupture area.Explanation
The size of an earthquake can be related to the rupture area. When an earthquake occurs, it is caused by the sudden release of energy along a fault line. The rupture area refers to the area of the fault that experiences displacement during the earthquake. The larger the rupture area, the more energy is released, resulting in a larger earthquake. Therefore, the size of an earthquake can be directly linked to the extent of the fault rupture area.Rate this question:
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- 37.
How do rock particles move during the passage of an S wave through the rock?
- A.
In a rolling circular motion
- B.
In a rolling elliptical motion
- C.
Back and forth at right angles to the direction of wave travel
- D.
Back and forth parallel to the direction of wave travel
Correct Answer
C. Back and forth at right angles to the direction of wave travelExplanation
During the passage of an S wave through the rock, the rock particles move back and forth at right angles to the direction of wave travel. This means that the particles oscillate side to side, perpendicular to the direction in which the wave is moving. This motion is characteristic of shear waves, which cause the material to deform by sliding or shearing.Rate this question:
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- 38.
How thick is average lithosphere?
- A.
250 km
- B.
1000 km
- C.
100 km
- D.
25 km
Correct Answer
C. 100 kmExplanation
The average thickness of the lithosphere is 100 km. The lithosphere is the rigid outer layer of the Earth, consisting of the crust and the uppermost part of the mantle. It is divided into tectonic plates that float on the semi-fluid asthenosphere below. The thickness of the lithosphere can vary depending on factors such as the type of crust (continental or oceanic) and the location (e.g., under mountains or ocean basins). However, on average, it is approximately 100 km thick.Rate this question:
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- 39.
As a rule of thumb aftershocks are typically ____ order(s) of magnitude ____ than the mainshock.
- A.
2; higher
- B.
1; higher
- C.
2; lower
- D.
1; lower
Correct Answer
A. 2; higherExplanation
Aftershocks are typically of a higher order of magnitude than the mainshock. This means that the magnitude of the aftershocks is usually greater than the magnitude of the mainshock. Aftershocks occur as the Earth's crust adjusts after a large earthquake, and they can continue for days, weeks, or even months following the mainshock. These aftershocks are generally smaller in magnitude compared to the mainshock but can still be significant and cause further damage.Rate this question:
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- 40.
What type of seismic wave causes the MOST building damage?
- A.
S waves
- B.
P waves
- C.
Surface waves
- D.
All seismic waves cause equal amounts of building damage.
Correct Answer
D. All seismic waves cause equal amounts of building damage.Explanation
This answer is correct because all seismic waves can cause building damage, but the degree of damage may vary depending on the type of wave and the characteristics of the building. P waves and S waves are body waves that travel through the Earth's interior, while surface waves travel along the Earth's surface. Surface waves, especially Love waves and Rayleigh waves, tend to cause the most damage to buildings as they produce strong shaking and have longer periods, which can resonate with the natural frequency of buildings leading to structural damage.Rate this question:
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- 41.
Which of the following statements BEST describes the current state of earthquake prediction?
- A.
Scientists can accurately predict the time and location of approximately 50 percent of all earthquakes.
- B.
Scientists can accurately predict when an earthquake will occur, but not where.
- C.
Scientists CANNOT accurately predict most earthquakes.
- D.
Scientists can accurately predict the time and location of almost all earthquakes.
Correct Answer
C. Scientists CANNOT accurately predict most earthquakes. -
- 42.
In the case of tsunamis, advance warnings can sometimes be sent because
- A.
Sound waves travel ahead of the tsunami.
- B.
Airline pilots who witness tsunamis can call ahead
- C.
Tsunami waves come in pairs
- D.
Seismic waves travel faster than tsunamis
Correct Answer
D. Seismic waves travel faster than tsunamisExplanation
Seismic waves travel faster than tsunamis. Seismic waves are generated by earthquakes, which are the main cause of tsunamis. These waves travel through the Earth's crust and can be detected by seismographs, allowing scientists to quickly determine the location and magnitude of an earthquake. Since seismic waves travel at a much faster speed than tsunamis, the information about the earthquake can be relayed to coastal areas before the tsunami waves arrive, providing advance warning and giving people time to evacuate to safer areas.Rate this question:
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- 43.
As the distance to an earthquake increases,
- A.
The time between the arrival of the P and S waves decreases.
- B.
The elapsed time before the P waves arrive decreases.
- C.
The time between the arrival of the P and S waves increases.
- D.
The amount of ground shaking increases.
Correct Answer
C. The time between the arrival of the P and S waves increases.Explanation
As the distance to an earthquake increases, the time between the arrival of the P and S waves increases. This is because the P waves, which are faster, arrive before the S waves. The farther away the observer is from the earthquake, the longer it takes for the S waves to reach them after the P waves. Therefore, the time between the arrival of the P and S waves increases with distance.Rate this question:
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- 44.
Seismic wave speeds increase with
- A.
Decreasing density and increasing temperature.
- B.
Increasing density and decreasing temperature.
- C.
Increasing density and temperature.
- D.
Decreasing density and temperature.
Correct Answer
B. Increasing density and decreasing temperature.Explanation
Seismic wave speeds are affected by the properties of the medium they travel through. As density increases, the particles in the medium become more closely packed, allowing seismic waves to propagate faster. On the other hand, as temperature decreases, the particles in the medium lose energy and vibrate less, resulting in a higher speed of seismic waves. Therefore, increasing density and decreasing temperature both contribute to an increase in seismic wave speeds.Rate this question:
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- 45.
What does the elastic rebound theory describe?
- A.
The fluctuations in groundwater prior to an earthquake
- B.
The uplift of the crust in response to erosion
- C.
The build-up and release of stress during an earthquake
- D.
The formation of mountain ranges by successive earthquakes
Correct Answer
C. The build-up and release of stress during an earthquakeExplanation
The elastic rebound theory describes the build-up and release of stress during an earthquake. This theory suggests that rocks on either side of a fault are continuously deformed and store elastic energy as stress builds up. When the stress exceeds the strength of the rocks, they suddenly break and release the stored energy, causing an earthquake. This process of elastic deformation and sudden release of energy is known as elastic rebound.Rate this question:
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- 46.
What causes the sharp increases in the velocity of S waves at a depth of 400 and 660 km in the mantle?
- A.
Changes in the pressure of the mantle
- B.
Changes in the composition of the mantle
- C.
Changes in the temperature of the mantle
- D.
Changes in the mineral structures
Correct Answer
D. Changes in the mineral structuresExplanation
The sharp increases in the velocity of S waves at a depth of 400 and 660 km in the mantle are caused by changes in the mineral structures. As seismic waves travel through the Earth's mantle, they encounter different mineral compositions and structures. These variations in mineral structures can cause changes in the velocity of the waves. At depths of 400 and 660 km, there are specific mineral phase transitions that occur, leading to sudden increases in the velocity of S waves. These changes in mineral structures play a significant role in understanding the composition and behavior of the Earth's interior.Rate this question:
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- 47.
Which of the following statements about groundwater in coastal regions is TRUE?
- A.
Seawater is denser than fresh water; therefore, fresh groundwater floats on top of salty groundwater.
- B.
Fresh water is denser than seawater; therefore, fresh groundwater floats on top of salty groundwater.
- C.
Seawater is denser than fresh water; therefore, salty groundwater floats on top of fresh groundwater.
- D.
Fresh water is denser than seawater; therefore, salty groundwater floats on top of fresh groundwater.
Correct Answer
A. Seawater is denser than fresh water; therefore, fresh groundwater floats on top of salty groundwater.Explanation
Seawater is denser than fresh water because it contains a higher concentration of dissolved salts. As a result, fresh groundwater, which is less dense, will float on top of salty groundwater in coastal regions. This is due to the principle of buoyancy, where denser fluids displace lighter fluids.Rate this question:
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- 48.
Which soil horizon consists primarily of slightly altered, weathered bedrock?
- A.
The C-horizon
- B.
The A-horizon
- C.
The B-horizon
- D.
None of the above
Correct Answer
A. The C-horizonExplanation
The C-horizon consists primarily of slightly altered, weathered bedrock. This horizon is located below the A and B horizons and is characterized by partially broken down parent material. It is less weathered and contains larger rock fragments compared to the other horizons. The C-horizon is important for soil formation as it provides a source of minerals and nutrients for plants.Rate this question:
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- 49.
Groundwater in agricultural areas may contain high quantities of _______ because of fertilizers.
- A.
Sodium
- B.
Calcium
- C.
Lead
- D.
Nitrate
Correct Answer
D. NitrateExplanation
Groundwater in agricultural areas may contain high quantities of nitrate because fertilizers used in farming often contain nitrogen-based compounds such as ammonium nitrate or urea. These fertilizers can leach into the soil and eventually make their way into groundwater, leading to elevated levels of nitrate. This is a common issue in agricultural regions where intensive farming practices are employed, and it can have negative impacts on both human health and the environment.Rate this question:
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- 50.
What causes the deep red color of soils found in Georgia and other warm, humid regions?
- A.
Iron oxides
- B.
Quartz
- C.
Feldspar
- D.
Clay minerals
Correct Answer
A. Iron oxidesExplanation
The deep red color of soils found in Georgia and other warm, humid regions is caused by iron oxides. Iron oxides are a group of minerals that contain iron and oxygen. When these minerals are present in the soil, they can give it a reddish hue. The warm and humid climate in these regions promotes the weathering of rocks and minerals, leading to the formation of iron oxides. These iron oxides then contribute to the characteristic deep red color of the soils in these areas.Rate this question:
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