OCN100: Class Quiz Questions

Note:  This page displays questions that are displayed and discussed during class lecture. These questions are meant to provide a guide to types of questions that may appear on an exam.  These questions are only a sample of the types of questions that may appear on the exam.  Students should use the study guide to make sure they are prepared for questions on a complete array of topics.

Week 1

1. What is a scientific theory?

2. The average depth of the sea floor is _________; the deepest place in the oceans is __________?

3. What invention made accurate open ocean navigation possible by determining longitude?

4. The 2 primary vessels now used in scientific ocean floor drilling are

5. How have oceanographers learned most about the geology of the seafloor?

Week 2

6.  Suppose a large portion of the island of Hawaii catastrophically slides into the Pacific Ocean.  The long-term effect on the remaining island would be

A. It would begin to rise
B. It would begin to sink
C. A new volcano would begin to grow
D. The tourist industry would be devastated

7.  In relation to plate tectonics, what is a major overall trend in earthquakes?

A.  Earthquakes occur at plate boundaries
B.  Earthquakes are not related to plate tectonics
C.  Earthquakes occur only when plates are moving very quickly at certain times of the year
D.  Earthquakes are related to volcanoes rather than plate tectonics

8.  The alternating reversals of Earth’s magnetic field throughout history have been recorded in sea floor rocks in a particular pattern.

A. This does not support plate tectonics
B. The pattern of alternating reversals indicates sea floor spreading
C. The pattern of alternating reversals indicates that the sea floor is static, and so there must be another mechanism for plate movement
D.  The pattern of alternating reversal indicates that the sea level has risen due to plate subduction

9.  Black smokers emit water in excess of 350 degrees Celsius, but release water rather than steam (water normally turns to steam at 100 degrees Celsius). Why is this so?

A. The water surrounding the smokers cools down the emitted water
B. The boiling point of water is much higher where black smokers occur due to higher pressure
C. The benthic life associated with black smokers prohibits the water from vaporizing
D.  None of the above

10. How does an ocean basin form?

A. Continental lithosphere becomes so dense that it sinks
B. Meteorite impacts cause huge craters that are the precursors to oceans
C. All of the ocean basins were formed when Earth’s crust first formed, so there are no new oceans
D. A continental plate is pulled apart and seafloor spreading creates ocean lithosphere in the gap left between the pieces
E. Heat and volcanism from Earth’s mantle can cause granitic continental crust to change into basaltic ocean crust

11. Actual spreading rates of new oceanic crustal material is close to

A. zero
B. 5 cm/yr
C. 35 cm/yr
D.  18 meter/yr

Week 3

12. All of the following are associated with a subduction zone EXCEPT

A. trench
B. very large earthquakes
C. hydrothermal vents
D. island arc
E. tsunami

13.  What happens when plate tectonics causes two continents to collide at a convergent plate boundary?

A. Subduction stops abruptly
B. One continent is subducted into the mantle
C. Neither continent will subduct, so they crumple and form a mountain range
D. The convergent boundary turns into a divergent or transform boundary
E.  A supercontinent is formed 

14. Which of the following will NOT happen to southern California?

A. We will be neighbors with San Francisco
B. We will slide toward the Aleutian trench
C. We will have earthquakes
D.  We will fall into the ocean

15. “Hot spots”

A.  are often associated with subduction zones
B.  are known for their relatively violent volcanic eruptions
C.  have a deep mantle source of heat
D.  move over time to form chains of islands on the sea floor

Week 4

16. What is the average depth of the outer edge of the continental shelf (i.e., the shelf break)?

A. 135 feet
B. 135 meters
C. 1.35 kilometers
D. 1350 meters
E. 13,500 feet

17. Why do abyssal plains not occur often in the Pacific Ocean?

A. The deep ocean trenches of the Pacific Ocean act like gutters that trap sediment transported off the land by turbidity currents
B. Turbidity currents travel directly down the continental margin and deposit sediment
C. Abyssal plains occur only in Earth’s eastern hemisphere
D. Abyssal plains do occur often in the Pacific Ocean

18.  Why is the East Coast of the United States considered a passive margin?

A. It is in close proximity to a plate boundary and experiences a high degree of tectonic activity
B. It is on a transform boundary, so it is passing another plate
C. It is far from any plate boundary and experiences no major tectonic activity
D. It is not considered a passive margin

19. What is the difference between a fracture zone and transform fault?

A. A transform fault is perpendicular to the mid-ocean ridge, but a fracture zone is not
B. They are two names for the same feature, a break in the plate formed by slip at a transform plate boundary
C. A transform fault is a crack, but a fracture zone is a hole in the crust
D. A transform has an active fault separating two plates, whereas a fracture zone is just the “scar” formed on one plate by the transform fault
E. A transform fault has strike-slip motion in reverse of the direction that the plates move apart, but a fracture zone has the opposite sense of motion

20. Where do most of the largest earthquakes occur?

A. Convergent plate boundaries
B. Divergent plate boundaries
C. Transform plate boundaries
D. At volcanic hotspots
E. In the center of continents

21.  From smallest to largest, which list of sediment textures is in the correct order?

A. Clay, sand, silt, pebbles
B. Clay, silt, sand, pebbles
C. Pebbles, sand, silt, clay
D. Silt, clay, pebbles, sand
E. Sand, silt, clay, pebbles

22.  On the whole, what is the most important process that transports sediments to the continental-margin?

A. Wind
B. Flowing water (rivers)
C. Ice (i.e., glaciers and icebergs)
D. Gravity (mass flows)
E. Volcanic eruptions

23.  Why is most lithogenous sediment composed of quartz?

A. Quartz is resistant to abrasion, extremely abundant, and extremely stable
B. Quartz is not a primary component of lithogenous sediment
C. Quartz is chemically unstable, and so becomes lithogenous sediment extremely easily
D. Lithogenous sediment forms in mid-ocean ridges where quartz is abundant

Week 5

24. By definition, an ooze is composed of greater than _____ of microscopic biogenous particles.

A. 10%
B. 20%
C. 30%
D. 40%
E. 50%

By the way... what makes up the other 70%?

25. Calcium carbonate ooze is generally found below regions of __________ surface water blanketing the ____________.

A. Cold / abyssal plains in the Pacific
B. Warm / mid-ocean ridges
C. Cold / high latitude Arctic & Antarctic shelves
D. Warm / mid-latitude continental shelves
E. Cold / continental margins

26. The Calcite Compensation Depth (CCD) is the depth in the ocean where ____________ equals ____________.

A. acidity – dissolution potential
B. temperature – the dissolution point
C. carbonate saturation – carbonate undersaturation
D. carbonate dissolution – carbonate supply
E. lysocline - thermocline

27. Most biogenic sediments consist of tiny shells called microfossils that are made of what two substances?

A. CaCO3 and MnO2
B. SiO2 and MnO2
C. SiO2 and CO2
D. CaCO3 and SiO2
E. CaCO3 and Fe3O4

28. The ______ Ocean basin has the most clay because_____?

A. Arctic / it is the coldest
B. Atlantic / it is the shallowest
C. Indian / it is the warmest
D. Pacific / it is the deepest
E. Antarctic / it has the most glacial ice

29. Why are the deep ocean basins covered with clay deposits?

A. Clay particles are carried to the middle of the oceans by wind and currents
B. Only the deep ocean has the right pressure, temperature, and oxygen conditions to form clay
C. Clay dominates because of the near absence of coarser lithogenous and biogenic particles
D. Clay is formed at hydrothermal vents, which are found in the deep sea

30. You are on a research cruise and you leave Japan, heading east. At about 1500 kilometers east of Japan you encounter a large volcanic plateau (Shatsky Rise) that is covered with sediments. You lower a piston core to sample the sediments and the wire indicator says 2500 meters of water depth. What kind of sediment will the core likely contain?

A. Lithogenous
B. Hydrogenous
C. Abyssal clays
D. Carbonate ooze
E. Siliceous ooze

Week 6

 31. Which of the following processes is NOT part of the traditional hydrologic cycle?

A. Water soaks into the soil to form groundwater
B. Water is locked up in ice in polar caps
C. Water flows from rivers to the oceans
D. Water is added to the oceans and atmosphere by volcanic activity
E. Water is evaporated from the oceans to form water vapor and clouds

32. Many of the unique properties of water, such as cohesion and its reputation as a universal solvent, come from its atomic structure. What causes these properties?

A. Atoms in water molecules are stuck together with atomic bonds
B. Atoms in water molecules are stuck together with covalent bonds
C. Water molecules are electrically polarized
D. Water molecules contain sodium (Na) ions that break down substances

33. What unit is defined as the amount of energy needed to raise the temperature of 1 gram of water by 1 degree centigrade?

A. Calorie
B. Van der Waals
C. Heat capacity
D. Kilocalorie
E. Joule

34. How does the latent heat of evaporation (and its equivalent, the latent heat of condensation) moderate climate?

A. It retards the formation of ice, keeping the oceans warmer
B. By absorbing energy on evaporation and releasing it on condensation, it keeps water cool when the air is hot, and warm when the air is cool
C. The endothermic reaction does not allow salt to build up past a certain concentration
D. The latent heat helps generate winds, which help keep the oceans cool when the air is hot

35. Why does ocean temperature change little from day to night?

A. Lesser cloudiness over the oceans allows them to soak up more solar energy than land
B. Salts in ocean water absorb sunlight during the day and release it at night
C. Stronger, more consistent winds over the ocean distribute heat evenly
D. High heat capacity absorbs solar energy quickly and releases it slowly

36. In the oceans, all of the following processes decrease local salinity except for one. Which process increases salinity?

A. Precipitation
B. River runoff
C. Evaporation
D. Sea ice melting
E. Icebergs melting

37. What does the principle of constant proportions tell us?

A. No matter where ocean salinity is measured, the result is the constant
B. No matter the salinity of ocean water, the ratios of major dissolved ions remains the same
C. The amount of chloride ions (Cl-) in ocean water is constant
D. Ocean water salts are dissolved ions

38. Complete the following statement. In seawater, carbon dioxide is added mostly by _____________; oxygen is added mostly by _____________.

A. respiration of marine organisms; photosynthesis
B. photosynthesis; wave action
C. wave action; respiration of marine organisms
D. volcanic activity; the atmosphere

Week 7-8

What causes most places on Earth to have seasons?

A. Earth is closer to the Sun in summer and farther away in winter
B. The spin axis is tilted 23.5 degrees to the plane of Earth’s orbit, causing solar radiation to vary in angle as Earth revolves around the Sun
C. The spin axis changes in tilt causing winter when the tilt is great and summer when the tilt is small
D. Days are longer during summer than winter, so the extra sunshine causes it to be warmer in summer and less sunshine causes it to be colder in winter

40. What causes the greenhouse effect?

A. Atmospheric gasses, such as water and carbon dioxide, absorb sunlight causing the atmosphere to heat up
B. The oceans absorb solar energy and trap heat, making the Earth warmer
C. Greenhouse gasses lead to polar ice cap melting, making the Earth warmer
D. Sunlight is absorbed by the Earth’s surface, reradiated as infrared energy, and absorbed by atmospheric gases

41. The sun heats Earth unevenly due to ___________.

A. wind belts
B. pressure of air changing from low to high
C. the Coriolis effect by the poles
D. the tilt of Earth’s rotational axis

42. In regard to Earth's heat budget, heat is transported by the ocean and atmosphere from.

A. the Atlantic to the Pacific
B. pole to Equator
C. Equator to pole
D. north pole to south pole

43. Globally, air descends (sinks toward the surface) at ______________.

A. the equator and 30 degrees latitude
B. the equator and 60 degrees latitude
C. 30 degrees latitude and 90 degrees latitude (the poles)
D. 30 degrees latitude and 60 degrees latitude

44. The ITCZ is an important region related to the global wind system. Ideally, it is located at the Equator. Which of the following applies to the ITCZ:

A. Most of the time it’s position is north of the Equator.
B. It is the place where hurricanes are generated.
C. It can be identified on a satellite view by a band of clouds.
D. All of the above apply

45. In the Northern Hemisphere, Ekman transport is

A. up
B. down
C. To the right
D. To the left

46. A system of currents including a drift current, an equatorial current and two boundary currents would be termed?

A. a gyre
B. an Ekman spiral
C. an eddy
D. a cyclone

47. Label each as a characteristic of Eastern (E) or Western (W) boundary currents

1. foggy desert climate (E)
2. warm & cold core rings (W)
3. Kuroshio Current (W)
4. upwelling and high ocean productivity (E)
5. wide current (E)
6. high volume (W)

48. Which of the following is true about equatorial countercurrents?

A. are best developed in the Atlantic
B. are sandwiched between the North and South Equatorial Currents
C. flow from east to west across each ocean basin [ W <------- E ]
D. all of the above are true

49. The Southern Ocean is dominated by what single large current?

A. The Antarctic Surface Water Current
B. The Antarctic Circumpolar Current (West Wind Drift)
C. East Wind Drift
D. Cromwell Current
E. Labrador Current

50. Large-scale wind-induced surface currents are measured primarily with __________.

A. chemical tracers
B. water properties
C. satellites
D. submerged floats
E. floating tub toys and shoes

51. Which deep waters have been isolated from the surface the longest?

A. North Atlantic Ocean
B. South Atlantic Ocean
C. Indian Ocean
D. South Pacific Ocean
E. North Pacific Ocean

52. What happens to a toy duck sitting on the water surface when waves pass by?

A. It moves in a nearly circular motion, always returning to the same spot
B. The wave fronts move it progressively forward as they pass
C. The wave troughs move it progressively backward as they pass
D. It moves up and down, but not forward or backward
E. It moves side-to-side, but not up and down

Week 9 & 10

53. If you were a submarine commander and wanted to go deep enough that your ship would not feel the effect of 300-foot wavelength storm waves, how deep would you have to dive?

A. Just beneath the surface
B. 300 feet
C. 150 feet
D. 600 feet
E. You would feel the waves all the way to the bottom, no matter how deep

54. If you have two deep-water waves with periods of 5 and 10 seconds, what can you say about their speeds?

A. The speeds are equal
B. The shorter period wave will have greater speed
C. The longer period wave will have greater speed
D. The longer period wave will have more than twice the speed
E.  They are both faster than a wave with a wavelength of 200 meters

55. What are the primary factors that determine wave height?

A. Wind speed and fetch
B. Wind speed, length of time wind blows in one direction, and fetch
C. Time that the wind blows from one direction
D. Water surface tension and wind
E. Wind speed and the time that the wind blows in one direction

56. A wave has a L = 50m and is traveling in water with a depth of 30m. It is a

A. Deep water wave
B. Shallow water wave
C. Can’t determine

57. Which of the following is NOT a physical change that a wave experiences as the wave reaches shallow water?

A. The wave “feels bottom”
B. The wavelength increases
C. The wave height increases
D. The wave steepness increases
E. The wave speed decreases

58. Wave reflection is explained by which of the following?

A. Waves bending backwards to resemble other waves in a mirror-like form
B. The bouncing back of wave energy caused by waves striking a hard barrier
C. The bouncing back of wave energy when more energy is inputted
D. The bending of waves in slow shallow water

59. Which of the following mechanisms is NOT a cause for tsunamis?

A. Large meteor impacts
B. Earthquakes
C. Submarine landslides
D. Lunar tides
E.  Volcanic eruptions

Week 11

60. The lunar tidal bulge has a period of 12 hours and 25 minutes, but the solar tidal bulge period is 12 hours. Why the difference?

A. The Moon is closer than the Sun
B. The Moon has phases
C. The Moon moves around Earth in its orbit
D. The Sun is bigger than the Moon
E. The Moon’s orbit is at a bigger angle from the rotation axis

61. Tide pools are best exposed when water levels are very low. The best time to go would be?

A. Neap tide
B. Spring tide
C. Quarter moon

62. Considering the Earth, Sun and Moon, what conditions would create the maximum tidal range?

A. Full or new moon phase
B. Sun at perihelion (January)
C. Moon at perigee
D. Same declination
E. All of the above together

63. Why are spring tides highest when the Moon is near perigee?

A. The Moon is moving fastest in its orbit at that time
B. The Moon is farther from Earth, so gravitational force is greater
C. The difference between solar and lunar tides is maximum at this time
D. The Moon and Sun are lined up
E. The Moon is closer to the Earth, so gravitational force is greater

64. Below is a tide graph for Ketchikan, AK. Which of the following is true?

A. The type of tide is semi-diurnal.
B. New or full moon likely occurs on the 10th
C. The tidal range is smaller than that of San Diego

65. If a point on the coast experiences a semi-diurnal tide, what does the daily tide record show?

A. One high tide and one low tide per day
B. One high tide (half a tide) one day and one low tide the next
C. Either one or two high tides each day, as long as they don’t change much
D. Two nearly equal high tides and two nearly equal low tides each day
E. Two unequal high tides and two unequal low tides each day

66. What would tides be like on Earth if the Moon did not exist?

A. Tides would occur, but the tidal range would be greater
B. Tides would occur, but the tidal range would be reduced
C. There would be hardly any difference compared to the tides as we know them
D. There would be no tides on Earth.

Week 12 & 13

67. If you look at beach sand under a magnifying glass, what do you see?

A. Quartz grains
B. Shell fragments
C. Coral reef debris
D. Whatever sand-sized particles are available from local rivers and streams

68. In winter, sand from some beaches disappears. Where does it go?

A. The sand becomes buried in mud
B. The sand moves down the continental margin to the deep sea through submarine canyons
C. Winter wave action moves the sand offshore into bars, located just below the wave base
D. The sand is stuck in rivers until the winter waves subside
E. The sand is covered up by rocks brought in by strong winter waves

69. If you are at the beach and blunder into a rip current, how do you get out?

A. Swim really hard toward the beach
B. Swim perpendicular to the current until you are out (usually parallel to shore)
C. Ride out the current until it dissipates
D. Call 911 on your cell phone
E.  Dive under the current and swim toward shore

70. Longshore current generally flows in which direction(s) along the coasts of the United States?

A. Southward along the Atlantic, northward along the Pacific
B. Northward along the Pacific, southward along the Atlantic
C. Northward along both coasts
D. Southward along both coasts

71. What is not a main component of a beach compartment?

A. Offshore submarine canyons where sand is drained away
B. A series of rivers that supply sand to a beach
C. The beach itself where sand is moving due to longshore transport
D. The biosphere’s use of the beach as its environment

72. What would happen to longshore transport along the coast if rivers on the coast were dammed, trapping sand behind the dams?

A. The longshore current would become less
B. The longshore transport would become less
C. There would be no effect because sand would get through with water released from the dams
D. Sand from beaches upstream in the longshore current would replace the sand missing from the rivers
E. Sand in the longshore current would be replaced by finer grained sediments from the rivers

73. What is the purpose of hard stabilization?

A. To decelerate coastal winds
B. To increase biodiversity along a coast
C. To protect a coast from erosion
D. To be used as an alternative to groin fields

74. What is the purpose of hard stabilization?

A. To decelerate coastal winds
B. To increase biodiversity along a coast
C. To protect a coast from erosion
D. To be used as an alternative to groin fields

75. What is an alternative to hard stabilization?

A. A seawall
B. A breakwater
C. The use of rip-rap
D. Beach nourishment

76. What would happen to a river delta if damming reduced the amount of sediment in the river?

A. Nothing much would change because the water flows through the delta
B. River water quality would improve
C. The delta would continue to grow as long as the river flows
D. The delta would erode and subside below sea level

77. During a hurricane, which of the following is UNLIKELY to occur on a barrier island?

A. Increased longshore transport will erode much sand from the beaches
B. TV reporters will lean into the wind and rain on camera to appear heroic
C. Waves and storm surge will cover large parts of the island
D. Wave erosion will cut new passes through the island
E. There will be little change in size and shape to the island

78. Which of the following mechanisms of sea level change is NOT eustatic?

A. Changes in global temperature
B. Changes in seafloor spreading rate
C. Formation of continental glaciers and ice caps
D. Glacial isostatic subsidence and rebound

Week 14-15

79. What is the defining characteristic of an estuary?

a. A partly enclosed body of water in which salinity is dictated by mixing of fresh water runoff and ocean water
b. A partly enclosed body of water located on the coast
c. A partly enclosed shallow body of water located on the coast
d. A place where animals that survive in brackish water live
e. An enclosed body of water on the coast that is cut off from the ocean

80. What is the most common type of estuary on the U.S. East and Gulf coasts?

a. Tectonic estuary (a.k.a. drowned tectonic valley)
b. Fjord (a.k.a. drowned glacial valley)
c. Coastal plain estuary (a.k.a. drowned river valley)
d. Bar-built estuary
e. Isostatic estuary

81. In general, what is the most common thing to happen when fresh water runoff meets ocean water in an estuary?

a. Salt water rides up over top of fresh water coming from land
b. Fresh water forms a layer on top of a layer of salt water at the bottom
c. The two water types mix completely in the center of the estuary
d. The Coriolis effect causes both to go to the right (in the northern hemisphere) so the ocean water coming in goes to one side and the fresh water going out goes to the other

 82. What is the primary difference between pelagic environment zones below the photic zone?

a. Increasing pressure with increasing depth
b. Decreasing oxygen with increasing depth
c. Decreasing light with increasing depth
d. Increase in salinity with decreasing temperature
e. Decreasing food abundance with increasing depth

83. Plankton are organisms that float. Why is a copepod, which can swim and propel itself through the water, classified as plankton?

a. It lives at the surface of the ocean where plankton live
b. It was classified as a plankton before it was known that copepods are swimmers
c. It has a swim bladder that keeps it from sinking, so it is a floater
d. It spends part of its life floating and part swimming, so it is classified as plankton because of the floating part
e. Because of its small size, it cannot swim very fast or very far, so its location is determined by currents

84. Of Earth’s total number of species, why are the fewest in the marine pelagic realm?

a. There is more area on land for different species
b. Uniform conditions in the pelagic realm make fewer specialized environments for organism adaptation as different species
c. Organisms need a hard substrate (either land or sea bottom) in order to evolve into different species
d. The pelagic realm contains the photic zone, and solar radiation in the photic zone suppresses the number of new species that evolve

85. What marine organism represents the vast majority of the ocean’s biomass?

a. Plankton
b. Sea cucumbers
c. Shrimp
d. Fish
e. Crustaceans

86. Why do most fish and marine mammals have the same torpedo-like, streamlined shape?

a. A streamlined shape presents a greater surface area to volume ratio, which allows easier regulation of internal heat
b. Streamlining looks better to the opposite sex, so it leads to greater reproduction
c. The streamlined shape minimizes energy expended to move through the water
d. They can swim faster with streamlined shapes

87. Most fresh water fish are hypertonic, meaning their body cells contain more salt than the surrounding water. Since osmosis should push water into their cells, why don’t they explode?

a. They urinate a lot, so the water does not build up
b. They don’t drink any water, since they get so much from osmosis
c. Their cells have adapted to absorb salt
d. They have adapted to live with high osmotic pressure
e. All of the above

88. Which of the following is an incorrect statement about the marine environment?

a. Pressure is generally greater than on land
b. Free oxygen is more abundant than the terrestrial environment
c. Temperatures are more stable than on land
d. Salinity is an issue in the ocean but not on land
e. Because of the viscosity difference between water and air, it is much easier for organisms to move through the air

89. What is a probable reason why land species represent 86% of the world’s species, whereas marine species only represent 14%?

a. There is more land on Earth than there is ocean
b. Water slows down the evolutionary process
c. The more variable the environment, the more chances there will be for new species to form and the ocean is more stable than the land environment
d. An underwater cataclysmic event during the Pleistocene killed many marine species which reduced the previously abundant marine species count to less than the number of land species

Week 16

Biological oceanographers discuss biomass frequently. Just what is biomass?

A. The amount of organisms produced in a given time
B. The total weight of protoplasm contained in a given organism
C. The total mass of all organisms of a given class
D. The total number of organisms within a given class

What are the two primary factors that control biologic productivity in the surface oceans?

A. Sunlight and temperature
B. Temperature and sunlight
C. Temperature and nutrients
D. Sunlight and nutrients
E. Sunlight and oxygen

Why is upwelling such an important factor in creating areas of high biologic productivity?

A. Upwelling brings nutrient-rich deep water to the surface where productivity is limited by the availability of nutrients
B. Upwelling delivers oxygen-rich water to the surface where productivity is limited by oxygen content in the water
C. Upwelling brings new phytoplankton to the surface where they can multiply rapidly
D. Upwelling causes rain, which results in less salty surface waters that are better suited for primary productivity

 Which of the three areas of the ocean typically has the greatest total productivity

A. Tropical oceans
B. Temperate oceans
C. Polar oceans

Which of the following statements is true about regional productivity

A. Productivity in tropical oceans is limited by nutrient availability due to a strong thermocline year-round
B. Productivity in temperate oceans is limited by sunlight in the winter, but nutrients are available year-round
C. Productivity in polar oceans is limited by nutrient availability year-round
D. All of the above are correct

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