The Emergency Alert System (Eas) Quiz
- 1.
Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface?
- A.
Poopoopedo
- B.
Pupu
- C.
Poipoipu
- D.
Pahoehoe
- E.
Papaya
Correct Answer
D. PahoehoeExplanation
Pahoehoe is a type of basaltic lava flow that has a fairly smooth, unfragmented, and ropy surface. This type of lava flow forms when the lava is very fluid and flows slowly, allowing it to cool and solidify in a smooth, undulating surface. The ropy texture is a result of the movement and folding of the still-molten interior of the lava flow as it cools. Pahoehoe lava flows are commonly found in areas with low slope gradients and can create unique and visually striking landscapes.Rate this question:
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- 2.
The carbonate compensation depth is
- A.
The depth where diatoms dissolve and do not accumulate in marine sediments
- B.
The level below which calcite and aragonite accumulate in ocean sediments
- C.
An ocean depth characterized by very low concentrations of dissolved carbon dioxide
- D.
The ocean depth at which carbonate supply rate is matched by carbonate dissolution rate
- E.
The depth where it is profitable to mine carbonates from the ocean floor
Correct Answer
D. The ocean depth at which carbonate supply rate is matched by carbonate dissolution rateExplanation
The carbonate compensation depth refers to the ocean depth at which the rate at which carbonate is supplied to the sediments is equal to the rate at which it is dissolved. This means that below this depth, calcite and aragonite accumulate in ocean sediments, while above this depth, diatoms dissolve and do not accumulate in marine sediments. It is important to note that the carbonate compensation depth is not related to the concentration of dissolved carbon dioxide or the profitability of mining carbonates from the ocean floor.Rate this question:
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- 3.
Waves begin to "feel bottom" when the depth of water is ________.
- A.
Equal to one seventh of the wavelength
- B.
Three times as great as the wavelength
- C.
Twice as great as the wavelength
- D.
Equal to one-half the wavelength
- E.
Equal to the wavelength
Correct Answer
D. Equal to one-half the wavelengthExplanation
When the depth of water is equal to one-half the wavelength, waves begin to "feel bottom". This means that the waves start to interact with the bottom of the body of water, causing changes in their behavior. At this depth, the wavelength is significant enough for the waves to be affected by the bottom, but not so deep that the waves are fully submerged and unaffected. Therefore, when the depth is equal to one-half the wavelength, the waves start to feel the bottom.Rate this question:
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- 4.
What type of faulting would be most likely to occur along the mid-Atlantic ridge?
- A.
Thrust faulting
- B.
Reverse faulting
- C.
Normal faulting
- D.
Advective faulting
- E.
Convective faulting
Correct Answer
C. Normal faultingExplanation
The most likely type of faulting to occur along the mid-Atlantic ridge is normal faulting. This is because the mid-Atlantic ridge is a divergent boundary, where tectonic plates are moving away from each other. Normal faulting occurs when tensional forces cause the hanging wall to move downward relative to the footwall. This type of faulting is commonly associated with divergent boundaries, where the Earth's crust is being pulled apart.Rate this question:
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- 5.
The boundary between the troposphere and stratosphere is defined by
- A.
The start of a temperature increase with increasing altitude
- B.
The start of a temperature decrease with increasing altitude
- C.
A big increase in the concentration of nitrogen
- D.
A big increase in the concentration of carbon dioxide
- E.
None of the above
Correct Answer
A. The start of a temperature increase with increasing altitudeExplanation
The correct answer is "the start of a temperature increase with increasing altitude." The boundary between the troposphere and stratosphere is defined by a change in temperature with increasing altitude. In the troposphere, temperature generally decreases with altitude, while in the stratosphere, temperature increases with altitude. This temperature inversion is caused by the presence of the ozone layer in the stratosphere, which absorbs and traps solar radiation, leading to a temperature increase. Therefore, the point where the temperature starts to increase marks the boundary between the troposphere and stratosphere.Rate this question:
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- 6.
How do calcareous oozes on the flanks of mid-ocean ridges form?
- A.
Calcite particles precipitate directly from seawater at all ocean depths and sink to the bottom
- B.
Calcite particles are formed by bottom-dwelling organisms
- C.
Calcite particles settle out from calcite-rich turbidity currents
- D.
Calcite particles are formed by organisms in the aphotic zone and sink to the bottom
- E.
Calcite particles are formed by organisms in the photic zone and sink to the bottom.
Correct Answer
E. Calcite particles are formed by organisms in the photic zone and sink to the bottom. -
- 7.
Coccolithophores are
- A.
Photosynthetic plankton with silica shells
- B.
Photosynthetic plankton with aragonite shells
- C.
Non-photosynthetic zooplankton with chitin exoskeletons
- D.
Non-photosynthetic plankton with calcite shells
- E.
Photosynthetic plankton with calcite shells
Correct Answer
E. Photosynthetic plankton with calcite shellsExplanation
Coccolithophores are photosynthetic plankton, meaning they can convert sunlight into energy through photosynthesis. They have calcite shells, which are made of calcium carbonate. These shells provide protection and support for the coccolithophores. The calcite shells also play a role in the carbon cycle, as they can sink to the ocean floor and sequester carbon dioxide. Therefore, the correct answer is "Photosynthetic plankton with calcite shells."Rate this question:
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- 8.
________ refers to the tendency for a foundation material to lose its internal cohesion and fail mechanically during earthquake shaking.
- A.
Liquefaction
- B.
Liquefaction
- C.
Motion slip
- D.
Occultation
- E.
Seismoflowage
Correct Answer
A. LiquefactionExplanation
Liquefaction refers to the phenomenon where a foundation material loses its internal cohesion and fails mechanically during earthquake shaking. This occurs when loose, water-saturated soil experiences rapid shaking, causing the water pressure between soil particles to increase. As a result, the soil loses its strength and behaves like a liquid, leading to the failure of structures built on top of it. Liquefaction can cause significant damage to buildings, bridges, and other infrastructure during earthquakes.Rate this question:
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- 9.
Drainage basins are separated by imaginary lines called
- A.
Aquifiers
- B.
Divides
- C.
Topography
- D.
Aquitards
- E.
None of the above
Correct Answer
B. DividesExplanation
Drainage basins are separated by imaginary lines called divides. These divides are elevated areas of land that separate the flow of water into different drainage basins. They act as boundaries, determining the direction in which water will flow. Aquifers are underground layers of rock or sediment that hold water, while aquitards are layers of impermeable rock that prevent the flow of water. Topography refers to the physical features of the land. None of the other options accurately describe the lines that separate drainage basins.Rate this question:
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- 10.
The Aleutian Islands occur at a ________.
- A.
Divergent boundary where shield volcanoes are forming
- B.
Transform boundary where North America has moved towards Alaska
- C.
Convergent, continental margin with uplifted fault blocks, much like those of the Basin and Range Province
- D.
Deep mantle hot spot
- E.
Convergent boundary on a volcanic arc above a northward-subducting Pacific plate
Correct Answer
E. Convergent boundary on a volcanic arc above a northward-subducting Pacific plateExplanation
The Aleutian Islands occur at a convergent boundary on a volcanic arc above a northward-subducting Pacific plate. This means that the Pacific plate is moving towards the North American plate, causing subduction to occur. As the Pacific plate subducts beneath the North American plate, it creates a volcanic arc, which is where the Aleutian Islands are located. This explains why shield volcanoes are forming in this region.Rate this question:
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- 11.
The most common Precambrian fossils are layered mounds of calcium carbonate called
- A.
Prokaryotes
- B.
Eukaryotes
- C.
Stromatolites
- D.
Trilobites
- E.
None of the above
Correct Answer
C. StromatolitesExplanation
Stromatolites are the most common Precambrian fossils. These are layered mounds of calcium carbonate formed by the growth of cyanobacteria, which are prokaryotes. Stromatolites provide evidence of early life on Earth and are important in understanding the history of the planet. Eukaryotes and trilobites are not associated with Precambrian fossils, and "none of the above" is not the correct answer as stromatolites are indeed the most common fossils from that time period.Rate this question:
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- 12.
________ denotes the exposed, crescent-shaped rupture surface at the head of a slump
- A.
Horst
- B.
Scarp
- C.
Ledge
- D.
Sole
- E.
Laccolith
Correct Answer
B. ScarpExplanation
A scarp is a steep slope or cliff that forms when a slump occurs. A slump is a type of mass movement where a block of material slides down a slope, leaving behind a crescent-shaped rupture surface at the head. Therefore, a scarp is the correct answer as it best describes the exposed, crescent-shaped rupture surface at the head of a slump. A horst refers to an uplifted block of crust between two parallel faults, a ledge is a narrow, horizontal shelf-like projection, a sole is the bottom surface of a sedimentary layer, and a laccolith is a dome-shaped intrusion of magma.Rate this question:
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- 13.
The ________ period was a time of major extinctions, including 75 percent of amphibian families
- A.
Devonian
- B.
Mississippian
- C.
Pennsylvanian
- D.
Permian
- E.
Jurassic
Correct Answer
D. PermianExplanation
The Permian period was a time of major extinctions, including 75 percent of amphibian families. This period, which occurred approximately 299 to 251 million years ago, marked the end of the Paleozoic Era. It is known for the mass extinction event called the Permian-Triassic extinction event, which is considered the most severe extinction event in Earth's history. This event led to the disappearance of many marine and terrestrial species, including a significant number of amphibians.Rate this question:
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- 14.
The two most common elements in the Earth's crust are ___________
- A.
Calcium and carbon
- B.
Iron and magnesium
- C.
Iron and sulfur
- D.
Chlorine and sodium
- E.
Silicon and oxygen
Correct Answer
E. Silicon and oxygenExplanation
Silicon and oxygen are the two most common elements in the Earth's crust. This is because silicon and oxygen make up the majority of minerals found in the crust, such as quartz and feldspar. These minerals are abundant and widely distributed throughout the Earth's crust, making silicon and oxygen the most common elements.Rate this question:
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- 15.
________ most effectively outline the edges of asthenospheric plates.
- A.
Lines of earthquake epicenters
- B.
Gravitational anomalies
- C.
The locations of deep mantle hot spots
- D.
Lines of active stratovolcanoes
- E.
None of the above
Correct Answer
E. None of the above -
- 16.
Due to a virtual absence of land plants and certain animals, fossil fuels are notably absent in ________ rocks.
- A.
Paleozoic and Mesozoic
- B.
Paleozoic
- C.
Cenozoic
- D.
Mesozoic
- E.
Precambrian
Correct Answer
E. PrecambrianExplanation
Fossil fuels are formed from the remains of plants and animals that lived millions of years ago. The Precambrian period refers to the time before the emergence of complex life forms, such as land plants and certain animals. Therefore, it is expected that fossil fuels would be notably absent in Precambrian rocks.Rate this question:
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- 17.
In the deep waters (greater than 1000 m) of the ocean concentrations of the vital nutrient nitrogen are:
- A.
Same in the Atlantic and Pacific
- B.
Dependent on levels of deep water photosynthesis
- C.
Lowest in the Atlantic, highest in the Pacific
- D.
Highest in the Atlantic, lowest in the Pacific
- E.
Highly variable in the Atlantic and Pacific depending on the season
Correct Answer
C. Lowest in the Atlantic, highest in the PacificExplanation
In the deep waters of the ocean, concentrations of the vital nutrient nitrogen are lowest in the Atlantic and highest in the Pacific. This suggests that the Pacific Ocean has a higher abundance of nitrogen compared to the Atlantic Ocean. The difference in nitrogen concentrations between the two oceans may be due to various factors such as differences in ocean currents, upwelling of nutrient-rich waters, and levels of deep water photosynthesis. However, the given answer does not mention the specific reasons for the difference in nitrogen concentrations.Rate this question:
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- 18.
A geologist observes a river with large bends and meanders in a 300 meter deep steep walled valley. The geologist correctly interprets that the
- A.
Land containing the river is atastic
- B.
Land containing the river has subsided
- C.
Sea level has risen
- D.
Land containing the river has been uplifted
- E.
None of the above
Correct Answer
D. Land containing the river has been upliftedExplanation
The geologist correctly interprets that the land containing the river has been uplifted. This is because the presence of large bends and meanders in the river indicates that the river has been flowing for a long time and has eroded the surrounding land. The steep-walled valley suggests that the land has been uplifted, as erosion alone would not create such deep valleys. Therefore, the uplift of the land is the most plausible explanation for the observed features.Rate this question:
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- 19.
The Earth's magnetic field originates by ________.
- A.
Magnetic mineral grains in the inner core
- B.
Magnetization of oxygen and nitrogen atoms in the atmospheric ozone layer by solar radiation
- C.
Weak electrical currents associated with hot, rising, mantle plumes
- D.
Weak electrical currents associated with fluid motions in the outer core
- E.
None of the above
Correct Answer
D. Weak electrical currents associated with fluid motions in the outer coreExplanation
The Earth's magnetic field originates from weak electrical currents associated with fluid motions in the outer core. These fluid motions are believed to be caused by the convection of molten iron and nickel in the outer core, which generates electrical currents due to the motion of charged particles. These electrical currents create a magnetic field that surrounds the Earth and extends into space. The magnetic field plays a crucial role in protecting the Earth from harmful solar radiation and helps in navigation by acting as a compass for many animals.Rate this question:
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- 20.
Variations in solar radiation reaching the earth over 20 to 100 thousand year time scales
- A.
Are explained in part by variations in solar occlusion and parallax
- B.
Are explained in part by variations in the eccentricity, obliquity and precession of the Earth's orbit.
- C.
Are explained in part by isotopic fractionation.
- D.
A and b
- E.
None of the above
Correct Answer
B. Are explained in part by variations in the eccentricity, obliquity and precession of the Earth's orbit.Explanation
Variations in solar radiation reaching the earth over long time scales can be attributed to variations in the eccentricity, obliquity, and precession of the Earth's orbit. These orbital parameters affect the distance between the Earth and the Sun, the tilt of the Earth's axis, and the orientation of the Earth's axis, respectively. Changes in these factors can lead to changes in the amount and distribution of solar radiation reaching different parts of the Earth, resulting in variations in solar radiation over thousands of years.Rate this question:
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- 21.
In correct order from the center outward, Earth includes which units or regions?
- A.
Inner core, outer core, lower mantle, asthenosphere, crust
- B.
Inner core, lithosphere, lower mantle, asthenosphere, crust
- C.
Inner core, outer core, lithosphere, mantle, asthenosphere
- D.
Inner core, outer core, lower mantle, astrosphere, crust
- E.
Inner core, inner mantle, outer core, asthenosphere, crust
Correct Answer
A. Inner core, outer core, lower mantle, asthenosphere, crust -
- 22.
Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.
- A.
Normal magnetizations along the rift valleys and reverse magnetizations along the ridge
- B.
Concentric circles about a rising plume of hot mantle rocks and magma
- C.
Normal and reversed magnetized strips roughly parallel to the ridge
- D.
Reversed magnetizations along the rift valleys and normal magnetizations along the ridge
- E.
Normal and reversed magnetized strips roughly perpendicular to the ridge axis
Correct Answer
C. Normal and reversed magnetized strips roughly parallel to the ridgeExplanation
The linear, magnetic patterns associated with mid-ocean ridges are configured as normal and reversed magnetized strips roughly parallel to the ridge. This means that the rocks on either side of the ridge have different magnetic orientations, with some having a normal magnetization and others having a reversed magnetization. These strips of alternating magnetic orientations provide evidence for seafloor spreading and the movement of tectonic plates.Rate this question:
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- 23.
In an El Nino year, near surface waters off Peru become _______.
- A.
Warmer than normal and nutrient poor
- B.
More benthic
- C.
Colder than normal and nutrient rich
- D.
Colder than normal and nutrient poor
- E.
Warmer than normal and nutrient rich
Correct Answer
A. Warmer than normal and nutrient poorExplanation
In an El Nino year, the near surface waters off Peru become warmer than normal. This is because El Nino is characterized by the warming of the surface waters in the eastern Pacific Ocean. Additionally, these waters become nutrient poor. This is because the warm waters disrupt the upwelling of nutrient-rich deep waters, leading to a decrease in nutrients available for marine organisms.Rate this question:
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- 24.
By the close of the Paleozoic, all the continents had fused into the single super continent of ________.
- A.
Europa
- B.
Pangea
- C.
Laurasia
- D.
Appalachia
- E.
Gondwanaland
Correct Answer
B. PangeaExplanation
By the close of the Paleozoic era, all the continents had merged together to form a single supercontinent called Pangea. This process, known as continental drift, occurred over millions of years as the tectonic plates shifted and collided. Pangea was a massive landmass that included present-day continents such as North America, South America, Africa, Europe, and Asia. The formation of Pangea had significant geological and biological implications, including changes in climate and the evolution of new species.Rate this question:
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- 25.
Approximately how much more energy is released in a 6.5 Richter magnitude earthquake than in one with magnitude 5.5?
- A.
2x
- B.
30x
- C.
100x
- D.
1000x
- E.
5x
Correct Answer
B. 30xExplanation
An earthquake with a magnitude of 6.5 releases approximately 30 times more energy than one with a magnitude of 5.5. The Richter scale is logarithmic, meaning that each increase of one magnitude represents a tenfold increase in the amplitude of seismic waves and approximately 31.6 times more energy release. Therefore, the difference between a magnitude 6.5 earthquake and a magnitude 5.5 earthquake is approximately 30 times in terms of energy released.Rate this question:
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- 26.
Mount St. Helens is ________.
- A.
An explosive ultramafic stratovolcano
- B.
An exposive andesitic shield volcano
- C.
An explosive basaltic cinder cone
- D.
An explosive andesitic stratovolcano
- E.
An explosive basaltic shield volcano
Correct Answer
D. An explosive andesitic stratovolcanoExplanation
Mount St. Helens is classified as an explosive andesitic stratovolcano. This means that it is a volcano composed of layers of hardened lava, ash, and other volcanic materials. It is characterized by its explosive eruptions and the presence of andesitic magma, which is rich in silica and has a higher viscosity compared to basaltic magma. The explosive nature of Mount St. Helens is due to the buildup of pressure from the gas-rich magma beneath the volcano, leading to violent eruptions.Rate this question:
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- 27.
The ________ zone is the near-surface zone of the ocean where light is strong enough for photosynthesis to occur.
- A.
Chloroplastic
- B.
Aphotic
- C.
Synphotic
- D.
Naviphotic
- E.
Euphotic
Correct Answer
E. EuphoticExplanation
The euphotic zone is the near-surface zone of the ocean where light is strong enough for photosynthesis to occur. This zone is characterized by high levels of sunlight penetration, allowing plants and algae to carry out photosynthesis and produce energy. The other options, such as chloroplastic, aphotic, synphotic, and naviphotic, do not accurately describe the zone where photosynthesis can occur in the ocean.Rate this question:
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- 28.
The last glacial maximum occurred approximately___________.
- A.
2,000 years ago
- B.
20,000 years ago
- C.
5,000 years ago
- D.
50,000 years ago
- E.
500,000 years ago
Correct Answer
B. 20,000 years agoExplanation
The last glacial maximum occurred approximately 20,000 years ago. This refers to a period in Earth's history when ice sheets were at their maximum extent during the last ice age. The Earth's climate was much colder during this time, with large portions of North America, Europe, and Asia covered in ice. The glacial maximum eventually gave way to a warming trend and the retreat of the ice sheets.Rate this question:
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- 29.
Which one of the following is true regarding tsunamis?
- A.
In the open ocean far from shore, wavelengths are many kilometers long and wave heights are typically 20 meters or more
- B.
In the open ocean far from shore, wavelengths are are many kilometers long and wave heights are often 3 meters or less.
- C.
They are started by fault-induced, horizontal shifts in the seafloor that suddenly propel great masses of water in opposite directions.
- D.
Their wave heights decrease and wavelengths increase as they move into shallower water
- E.
None of the above
Correct Answer
B. In the open ocean far from shore, wavelengths are are many kilometers long and wave heights are often 3 meters or less.Explanation
In the open ocean far from shore, tsunamis have long wavelengths that can span many kilometers, but their wave heights are often relatively low, typically 3 meters or less. This is because the energy of the tsunami is spread out over a large area, causing the wave to be less pronounced in terms of height. As the tsunami approaches shallower water, its wave heights decrease even further and its wavelengths increase. Therefore, the correct answer is that in the open ocean far from shore, wavelengths are many kilometers long and wave heights are often 3 meters or less.Rate this question:
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- 30.
Sandstone strata and a mass of granite are observed to be in contact. Which of the following statements is correct geologically?
- A.
The sandstone is younger if it shows evidence of contact metamorphism
- B.
The granite is older if the sandstone contains pebbles of the granite.
- C.
The granite is older if it contains inclusions of sandstone.
- D.
The sandstone is younger if the granite contains sandstone inclusions
- E.
None of the above
Correct Answer
B. The granite is older if the sandstone contains pebbles of the granite.Explanation
If the sandstone contains pebbles of the granite, it suggests that the granite was present before the sandstone formed. This is because the pebbles would have been eroded from the granite and then incorporated into the sandstone during its formation. Therefore, the granite is older than the sandstone in this scenario.Rate this question:
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- 31.
Which of the following best describes bedded gypsum and halite?
- A.
Varieties of coal and peat
- B.
Varieties of dolostone
- C.
Detrital sedimentary rocks
- D.
Chemical metamorphic rocks
- E.
Evaporites; chemical, sedimentary rocks
Correct Answer
E. Evaporites; chemical, sedimentary rocksExplanation
Bedded gypsum and halite are evaporites, which means they form through the process of evaporation. They are chemical sedimentary rocks because they are composed of minerals that precipitate out of solution. Gypsum and halite are commonly found in arid or semi-arid environments where there is a high rate of evaporation, causing the minerals to crystallize and form layers or beds. Therefore, the answer "evaporites; chemical, sedimentary rocks" best describes bedded gypsum and halite.Rate this question:
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- 32.
Brittle deformation would be favored over plastic deformation in which of the following conditions?
- A.
Warmer temperatures
- B.
High confining pressures
- C.
Cooler temperatures
- D.
Low confining pressures
- E.
C and d
Correct Answer
E. C and dExplanation
Brittle deformation is favored over plastic deformation in cooler temperatures and low confining pressures. In cooler temperatures, the rocks become more rigid and less ductile, making them more prone to brittle failure. Similarly, in low confining pressures, there is less pressure acting on the rocks, allowing them to fracture more easily. Therefore, both cooler temperatures and low confining pressures promote brittle deformation.Rate this question:
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- 33.
A natural, meandering, river channel is modified into a straighter and smoother, canal-like channel. Which of the following statements is correct?
- A.
The natural channel had a lower gradient and less friction than the modified channel
- B.
The modified channel has a lower gradient and more friction than the natural channel
- C.
The modified channel has a higher gradient and more friction than the natural channel
- D.
The natural channel had a higher gradient and more friction than the modified channel
- E.
None of the above
Correct Answer
E. None of the aboveExplanation
The correct answer is "none of the above" because when a natural, meandering river channel is modified into a straighter and smoother, canal-like channel, the gradient of the channel may change but it is not necessarily higher or lower. Similarly, the amount of friction in the channel may also change but it is not necessarily more or less. Therefore, none of the statements accurately describe the relationship between the gradient and friction of the natural and modified channels.Rate this question:
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- 34.
Which one of the following best describes volcanism in the Cascade Range, northwestern United States?
- A.
Related to deep, transform faults
- B.
Related to a mantle hot spot
- C.
Related to a mid-oceanic ridge system
- D.
Related to plate subduction
- E.
Related to a continental rift zone
Correct Answer
D. Related to plate subductionExplanation
The correct answer is related to plate subduction. The Cascade Range in the northwestern United States is known for its volcanic activity, which is caused by the subduction of the Juan de Fuca Plate beneath the North American Plate. As the Juan de Fuca Plate sinks beneath the North American Plate, it creates a zone of intense heat and pressure, leading to the melting of rock and the formation of magma. This magma then rises to the surface, resulting in volcanic eruptions and the formation of the Cascade volcanoes.Rate this question:
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- 35.
Unconsolidated, finely ground material that is sometimes found in fault zones is termed___________.
- A.
Gouge
- B.
Ahulu
- C.
Seismoliths
- D.
Basalt
- E.
Tuff
Correct Answer
A. GougeExplanation
Unconsolidated, finely ground material that is sometimes found in fault zones is called "gouge." Gouge is formed through the grinding and crushing of rocks along a fault line, resulting in a mixture of fragmented rock particles. It is commonly composed of various rock types and can have a clay-like consistency. Gouge plays a significant role in fault mechanics and can affect the behavior of earthquakes.Rate this question:
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- 36.
A geologist finds a rock outcrop with crossbeds in a well-sorted quartz sandstone. The best interpretation for the depositional environment of this sandstone is ____.
- A.
A sand dune
- B.
A bajada
- C.
An oxbow lake
- D.
A ground moraine
- E.
A terminal moraine
Correct Answer
A. A sand duneExplanation
The presence of crossbeds in a well-sorted quartz sandstone suggests that the sediment was deposited by wind. Crossbeds are formed when wind or water transports and deposits sediment in inclined layers. In this case, the well-sorted nature of the sandstone indicates that the sediment was sorted and transported by wind, rather than water. Therefore, the best interpretation for the depositional environment of this sandstone is a sand dune, where wind-blown sand accumulates and forms distinct crossbeds.Rate this question:
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- 37.
A magma body can become more felsic by
- A.
Magmatic isotropism
- B.
Incorporation and melting peridotite
- C.
The crystallization of and settling of quartz and feldspar in a magma chamber.
- D.
A and b
- E.
None of the above
Correct Answer
E. None of the aboveExplanation
The correct answer is none of the above. A magma body can become more felsic through the process of fractional crystallization. This occurs when minerals with higher silica content, such as quartz and feldspar, crystallize and settle out of the magma chamber, leaving behind a more felsic residual melt. Magmatic isotropism refers to the uniform distribution of minerals within a magma body and does not directly contribute to the increase in felsic composition. Incorporation and melting of peridotite, which is a mafic rock, would actually lead to a decrease in felsic composition.Rate this question:
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- 38.
When waves reach shallow water, they are often bent and tend to become parallel to the shore. This process is termed ________.
- A.
Translation
- B.
Reflection
- C.
Oscillation
- D.
Refraction
- E.
None of the above
Correct Answer
D. RefractionExplanation
When waves reach shallow water, they undergo a process called refraction. Refraction occurs when waves change direction as they pass from one medium to another, in this case from deep water to shallow water. The change in direction is caused by the difference in wave speed between the two mediums. In shallow water, the bottom of the wave slows down, causing the top of the wave to move faster and bend towards the shore. This results in the waves becoming parallel to the shore.Rate this question:
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- 39.
Organisms at the base of the food chain near deep sea hydrothermal vent systems use ___________ to create organic molecules like proteins and carbohydrates
- A.
Chemosynthesis
- B.
Photogenesis
- C.
Photosynthesis
- D.
Parthenogenesis
- E.
None of the above
Correct Answer
A. ChemosynthesisExplanation
Chemosynthesis is the process by which organisms use chemicals, such as hydrogen sulfide or methane, to produce organic molecules like proteins and carbohydrates. This process occurs in deep sea hydrothermal vent systems where sunlight is not available for photosynthesis. Unlike photosynthesis, which uses sunlight as an energy source, chemosynthesis relies on the energy obtained from chemical reactions. Therefore, chemosynthesis is the correct answer for the given question.Rate this question:
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- 40.
The average composition of the continental crust most closely approximates that of ________.
- A.
Leaverite
- B.
Granite
- C.
Peridotite
- D.
Basalt
- E.
Rolandite
Correct Answer
B. GraniteExplanation
Granite is the correct answer because it is a common rock type found in the continental crust. The continental crust is primarily composed of granite, which is a type of igneous rock made up of minerals such as quartz, feldspar, and mica. This composition is consistent with the average composition of the continental crust, making granite the most closely approximated rock type.Rate this question:
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- 41.
If you start with 12000 atoms of a radioactive parent isotope, how many atoms of the parent isotope remain after 3 half lives?
- A.
3000
- B.
750
- C.
4000
- D.
1500
- E.
6000
Correct Answer
D. 1500Explanation
After each half-life, the amount of parent isotope remaining is reduced by half. So, after the first half-life, there will be 6000 atoms remaining. After the second half-life, there will be 3000 atoms remaining. And after the third half-life, there will be 1500 atoms remaining.Rate this question:
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- 42.
The relative stability of common minerals under weathering listed from the most stable to the least stable would be:
- A.
Quartz, calcite, aluminum hydroxides, potassium feldspar, amphiboles
- B.
Calcite, aluminum hydroxides, quartz, amphiboles, potassium feldspar
- C.
Quartz, calcite, potassium feldspar, amphiboles, aluminum hydroxides
- D.
Calcite, aluminum hydroxides, quartz, potassium feldspar, amphiboles
- E.
Aluminum hydroxides, quartz, potassium feldspar, amphiboles, calcite
Correct Answer
E. Aluminum hydroxides, quartz, potassium feldspar, amphiboles, calcite -
- 43.
Large circular structures with rock units dipping away from the center of the structure are called ________.
- A.
Domes
- B.
Synclines
- C.
Horsts
- D.
Basins
- E.
Anticlines
Correct Answer
A. DomesExplanation
Large circular structures with rock units dipping away from the center of the structure are called domes. Domes are formed by the uplifting of rock layers, causing them to bend and create a circular or dome-shaped structure. The rock layers in a dome typically dip away from the center, forming an anticlinal structure. Domes can be found in various geological formations and are often associated with the presence of igneous intrusions or the uplifting of underlying rock layers.Rate this question:
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- 44.
As the rate of cooling decreases, the size of the crystals that form in an intrusive igneous rock ________.
- A.
Increases
- B.
Depends on magma fecularity
- C.
Decreases
- D.
Is not affected
- E.
None of the above
Correct Answer
A. IncreasesExplanation
As the rate of cooling decreases, the size of the crystals that form in an intrusive igneous rock increases. This is because slower cooling allows more time for the atoms to arrange themselves into a regular pattern, resulting in larger crystals. On the other hand, rapid cooling leads to smaller crystals or even a glassy texture, as there is not enough time for the atoms to arrange themselves properly. Therefore, the correct answer is "increases".Rate this question:
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- 45.
This igneous texture is characterized by two distinctively different crystal sizes
- A.
Pyroclastic
- B.
Porphyria
- C.
Porifera
- D.
Pelagic
- E.
Porphyritic
Correct Answer
E. PorphyriticExplanation
Porphyritic texture is characterized by the presence of two distinctively different crystal sizes. This texture is commonly found in igneous rocks, where larger crystals (phenocrysts) are embedded in a fine-grained matrix (groundmass). The phenocrysts usually form first in the cooling magma, allowing them to grow larger before the remaining magma solidifies rapidly, resulting in the fine-grained groundmass. This texture suggests that the rock underwent two stages of cooling, with the phenocrysts forming in an earlier stage and the groundmass forming in a later stage.Rate this question:
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- 46.
Which one of the following is an example of an isostatic movement?
- A.
Motion of tsunami waves
- B.
Arching of strata at the center of a dome
- C.
Numerous aftershocks associated with deep-focus earthquakes
- D.
Uplift of areas recently covered by thick, continental ice sheets
- E.
Stream downcutting following a drop in sea level
Correct Answer
D. Uplift of areas recently covered by thick, continental ice sheetsExplanation
The uplift of areas recently covered by thick, continental ice sheets is an example of an isostatic movement. Isostatic movement refers to the vertical movement of Earth's crust in response to changes in the distribution of mass on the surface. When large ice sheets melt, the weight is removed from the land beneath, causing the crust to rebound and uplift. This is known as post-glacial rebound or isostatic rebound. Therefore, the uplift of areas recently covered by thick, continental ice sheets is a clear example of an isostatic movement.Rate this question:
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- 47.
Which igneous rock is the most abundant igneous rock of the crust and underlies virtually all of the floors of the ocean
- A.
Pumice
- B.
Andesite
- C.
Mylonite
- D.
Gneiss
- E.
Basalt
Correct Answer
E. BasaltExplanation
Basalt is the correct answer because it is the most abundant igneous rock in the Earth's crust and is found underneath the floors of the ocean. Basalt is formed from the solidification of molten lava and is characterized by its dark color and fine-grained texture. It is commonly found in volcanic areas and is a major component of oceanic crust.Rate this question:
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- 48.
The effects of the collision of a Mars-sized body with the Earth 4.5 million years ago is proposed to have caused_______
- A.
The Earth's spin axis to tilt
- B.
A magma ocean to form at the Earth's surface
- C.
An increase in the Earth's speed of rotation
- D.
Debris to be ejected that eventually formed the moon
- E.
None of the above, a Mars-sized body did not collide with the Earth 4.5 million years ago
Correct Answer
E. None of the above, a Mars-sized body did not collide with the Earth 4.5 million years ago -
- 49.
What are erratics?
- A.
Large boulders deposited randomly by glaciers
- B.
Conflicting dates of glaciation obtained by dating organic material found in glaciers
- C.
Cross-beds that do not match the overall outwash cross-bedding pattern
- D.
Valleys with ventifact striations
- E.
None of the above
Correct Answer
A. Large boulders deposited randomly by glaciersExplanation
Erratics are large boulders that have been deposited randomly by glaciers. As glaciers move, they pick up rocks and boulders from the ground and carry them along. When the glacier eventually melts, it leaves behind these boulders in different locations, often far away from their original source. These erratics can vary in size, from small rocks to massive boulders, and their presence is evidence of past glaciation in an area. They are an important geological feature that helps scientists understand the history and movement of glaciers.Rate this question:
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- 50.
A typical rate of seafloor spreading in the Atlantic Ocean is ________.
- A.
0.02 centimeters per year
- B.
20 centimeters per year
- C.
200 centimeters per year
- D.
2 centimeters per year
- E.
0.2 kilometers per year
Correct Answer
D. 2 centimeters per yearExplanation
The correct answer is 2 centimeters per year. This rate is considered typical for seafloor spreading in the Atlantic Ocean. This means that the oceanic crust is spreading apart at a rate of 2 centimeters per year, leading to the formation of new crust. This slow but continuous process contributes to the widening of the Atlantic Ocean over geologic time.Rate this question:
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Mar 21, 2023Quiz Edited by
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Dec 06, 2012Quiz Created by
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