Accounting
Anthropology
Archaeology
Art History
Banking
Biology & Life Science
Business
Business Communication
Business Development
Business Ethics
Business Law
Chemistry
Communication
Computer Science
Counseling
Criminal Law
Curriculum & Instruction
Design
Earth Science
Economic
Education
Engineering
Finance
History & Theory
Humanities
Human Resource
International Business
Investments & Securities
Journalism
Law
Management
Marketing
Medicine
Medicine & Health Science
Nursing
Philosophy
Physic
Psychology
Real Estate
Science
Social Science
Sociology
Special Education
Speech
Visual Arts
Earth Science
Q:
What happens when fresh water flows into seawater?
A) They mix completely.
B) The sea water covers the fresh water.
C) The fresh water covers the sea water.
D) There is a continuous gradation from fresh water on top to sea water on the bottom.
E) There is a continuous gradation from seawater on top to fresh water on the bottom.
Q:
Density is an important property of ocean water because ________.
A) it determines the chemistry of the water
B) it determines the horizontal position of the water
C) it determines the temperature of the water
D) it determines the vertical position of the water
E) it only changes when there is a major change in water chemistry
Q:
Discuss the distribution of seafloor sediments in the ocean basins. What are the different types of sediments, and what are the factors that control their distribution (geologic setting, climate, etc.)?
Q:
Examine Figure 13.B from Earth Science, 14e below. Briefly explain the main points of Charles Darwin's hypothesis on coral atoll formation. Have we tested his hypothesis and is it still thought to be correct today? Can you think of another possible explanation that would explain the origin of such coral atolls?
Q:
What type of continental margin is illustrated in the diagram below?
Q:
What energy resource is present in the oceans with far more energy reserves than conventional oil and gas?
Q:
The most important economic resource in the ocean today is ________.
Q:
Manganese nodules are an example of ________ sediment.
Q:
________ sediment consists of shells and hard parts of marine organisms.
Q:
A prominent feature of the Mid-Atlantic Ridge is a very deep linear valley known as a(n) ________ valley.
Q:
The most extensive mountain range on Earth extends for about 65,000 kilometers on the ocean floor and is known as the ________.
Q:
A(n) ________ marks the site where old, oceanic lithosphere begins its descent into a subduction zone.
Q:
A(n) ________ is the vast, relatively deep, flat, sediment-covered portion of the deep-ocean basin.
Q:
A(n) ________ is a volcanic mountain, built up from the seafloor that never reached the sea surface.
Q:
Flat-topped volcanic structures located on the floor of the deep ocean basin are termed ________.
Q:
________ continental margins typically exhibit wide, extensive, continental shelves.
Q:
Valleys that lead from the continental shelf into deeper waters are known as ________.
Q:
The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the ________.
Q:
________ continental margins occur where oceanic lithosphere is being subducted beneath the edge of a continent.
Q:
The principal technique for finding ocean depth today is ________.
Q:
The lowest point on earth is in the ________ Ocean.
Q:
Oil and gas resources are rare on the continental slope and continental rise.
Q:
The second most important economic mineral resource extracted from the seafloor today is manganese from manganese nodules.
Q:
Sand, silt, and clays deposited on the ocean floor are described as terrigenous sediments.
Q:
Turbidites and siliceous oozes are both biogenous sediments.
Q:
Manganese nodules do not accumulate below 4500 meters depth because the manganese minerals are highly soluble in seawater below that depth.
Q:
The Atlantic and Pacific basins have oceanic ridges; the Indian Ocean has no oceanic ridge.
Q:
Seafloor hot springs occur mainly in oceanic, abyssal plains.
Q:
Submerged, flat-topped seamounts are known as guyots.
Q:
Abyssal plains with sediments covering the seafloor igneous rocks are more extensive in the central Pacific basin than in the North Atlantic.
Q:
The continental rise lies at the bottom of the continental slope.
Q:
Submarine canyons form the deepest parts of the ocean basins.
Q:
The west coast of South America and the east coast of North America have very different continental margins.
Q:
Most of the world's landmass is in the northern hemisphere.
Q:
The deepest point in the ocean is in the Indonesian trench, off Sumatra, where the 2004 Earthquake occurred.
Q:
Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. manganese nodules
calcareous ooze
metal sulfides
evaporites
Q:
Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. rift valley
subduction
volcanic island arc
trench
Q:
Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. continental shelf
continental rise
continental slope
continental volcanic arc
Q:
Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. echo sounder
Doppler radar
sidescan sonar
radar altimeters
Q:
Give the term of ocean floor sediment for each phrase. biogenous
terrigenous
hydrogenous abyssal plain clay
Q:
Give the term of ocean floor sediment for each phrase. biogenous
terrigenous
hydrogenous calcareous ooze
Q:
Give the term of ocean floor sediment for each phrase. biogenous
terrigenous
hydrogenous manganese nodule
Q:
Why would a large concrete producing company be interested in the sea bed?
A) as a source of lime from sea shells
B) as a source of mud to mix with limestone to make Portland cement
C) They can rape the sea bed without being prosecuted like they would in operating a quarry or gravel pit improperly.
D) as a source of sand and gravel
Q:
The 2010 deep water horizon oil spill in the Gulf of Mexico was a tragedy brought on in part by new technology allowing development of oil and gas reserves in deep water. Given the scope of the spill, why would companies take a risk of such a disaster given the scope of the litigation following the disaster?
A) They didn't care about the risk, they just drove forward.
B) The oil and gas industry is poor at assessing risk, and didn't understand the risk.
C) The potential profit is so large from a major oil find that the companies take the risk, try to use all cautions to minimize risk, but sometimes fail.
D) They just assume their lawyers can win any lawsuit, regardless of the disaster.
Q:
Why isn't manganese mined on the seabed when there are abundant manganese nodules in some parts of the ocean floor?
A) The manganese is too difficult to extract from the nodules; a new technology is needed.
B) It is not economical to mine manganese nodules at present-day world prices for manganese and associated metals in nodules.
C) The manganese market is held by a global cartel who prevent the material from being mined.
D) It is impossible to extract the nodules from the seafloor with present-day technology.
Q:
In the present day, what is the most valuable non-living commodity obtained from sea floor?
A) sand and gravel
B) gold
C) oil and gas
D) gas hydrate
Q:
Most of our table salt comes from ________.
A) salt taken from mines
B) salt obtained by evaporating seawater in dry climates
C) combining the metal sodium and the nonmetal chlorine gas in a chemical reaction vessel to make pure NaCl
D) China
Q:
African dust from the Sahara desert is observed across the Atlantic as far west as the Caribbean region where it produces a hazy sky condition during the annual dry season. You are a climate scientist and make a prediction that the Sahara was not a desert during glacial periods in the northern hemisphere. How could you test this hypothesis by looking at deep sea sediments from the Atlantic off west Africa?
A) You would look at fossils to see if there were organisms that preferred dusty conditions vs. clear water conditions.
B) You could look at the sediments to see if there were biogenic sediments interbedded with sediments with terrigeneous input corresponding to the dry, interglacial intervals.
C) You could measure the isotopes in the sediment to estimate the sea surface temperatures.
D) The hypothesis is untestable with deep sea sediment.
Q:
When organisms living in seawater grow shells, the ratio between the isotopes of oxygen (18O/16O) trapped in their shell is dependent on the sea temperature. Why might geologists collect these sea shells from deep-sea sediments that are Pleistocene in age and measure their oxygen isotope ratios?
A) They might want to know how cold the water was at the seafloor in the past.
B) They want to know how metabolism of the organism affects the oxygen isotope ratios.
C) The organisms live in the photic zone, and so photosynthesis must be the main factor in the oxygen content.
D) The organisms live near the surface, so their oxygen isotope ratios record surface temperature during Earth's great climate fluctuations of the ice age.
Q:
Micro-organisms called foraminifera have tiny coiled shells with chambers, not unlike the chambering nautilus but much smaller. In modern oceans the coiling direction of foraminifera shells is correlated to temperature. Using coiling direction from foraminifera fossils is an example of ________.
A) using the fossil as a paleo-depth indicator because water temperature varies with depth
B) using the fossil's coiling direction is a proxy for climate because the surface water temperature would be highly correlated to surface temperature
C) using isotopes to fingerprint temperature
D) geomagic; the whole idea is preposterous
Q:
Much of the Gulf of Mexico is underlain by large thicknesses of salt that formed in a small ocean basin like the red sea, as the north Atlantic spreading began in Mesozoic time. This salt is a good example of ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Q:
A geologist is studying sediments on land that were originally deep sea sediments. She finds the minerals zircon and garnet in the sediments, which could only come from a continental region. These sediments must be ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Q:
Radiolarian chert is a common sedimentary rock accreted along active margins in the circum-pacific. It is produced in the deep sea by the accumulation of siliceous radiolarian shells. What kind of sediment is radiolarian chert?
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Q:
Minerals that crystallize directly from seawater are examples of ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Q:
Manganese nodules are an example of ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Q:
Sediments derived primarily from the products of weathering on the continents are called ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Q:
How do calcareous oozes form?
A) The particles are precipitated in warm surface waters and sink to the bottom.
B) The particles are precipitated by bottom-dwelling organisms.
C) The particles are precipitated in the water column below the depth of sunlight penetration and then sink to the bottom.
D) The particles settle out from calcite-rich turbidity currents at depths greater than 15,000 feet.
Q:
Why are there virtually no sediments at ocean ridges, even when they are close to land?
A) The sediments get buried by volcanic rocks, so are not visible.
B) The sediments get deflected from the topographic high of the ridge.
C) The crust is too young; there hasn't been enough time for sediments to accumulate.
D) No one knows, it is one of the mysteries of geology.
Q:
Convective cooling cools rocks much more rapidly than heat conduction. Hydrothermal circulation represents convective cooling at ocean ridges and is well known from things like black smokes, but only occurs close to the spreading ridge axis. When geophysicists measure the geothermal gradient in areas along ridges where there is no hydrothermal activity, the thermal gradient is far below what you would predict theoretically, but near hydrothermal vents it is far more than you would predict. Why would this be?
A) The measurements are incorrect because it is too hot to measure thermal gradient in molten rock.
B) Most of the heat is carried away by convection as hydrothermal systems, so the average geothermal gradient away from the hydrothermal circulation is depressed.
C) Organisms growing around hydrothermal vents disturb the thermal properties, insulating the surface, to make an apparent high thermal gradient.
D) The thermal gradient in water represented by the hydrothermal system must be different than the rock, so it is measurement artifact.
Q:
Earlier we discussed the concept of isostasy, where lower density rocks rise higher than higher density rocks. How is the variation of water depth at spreading centers (ridges) controlled by isostasy?
A) Volcanic rocks are lighter than other rocks, and so the abundant volcanic rocks at the ridges are lower density features that produce the seafloor topography.
B) It has nothing to do with isostasy; the areas are simply high because there are chains of active volcanos along the ridge crest, producing the topography.
C) Oceanic ridges are sites where the lithosphere is carried into the mantle on one side (aka subduction zones), and the volcanos along these margins produce the ridge by buildup of lower density crust.
D) The lithosphere cools as it moves away from the ridge axis by sea floor spreading, and cooler rocks are lower density, so the sea floor gets deeper as the lithosphere gets more dense.
Q:
The seafloor spreading process at ridges produces what kind of faults?
A) normal faults
B) thrust fault
C) strike-slip faults
D) oblique-slip faults
Q:
Ocean ridges form because ________.
A) rocks bulge up in ridges along transform faults associated with the ridge
B) they are a broad seafloor highland formed by sea floor spreading
C) they are submarine collisional mountain belts, forming submarine mountains that haven't yet risen from the sea floor
D) they are chains of volcanos, like the Hawaiian Islands, that form along hot spots
Q:
"Black smokers" are associated with ________.
A) oceanic ridges
B) mineral-rich waters
C) hot water
D) all of these
Q:
Which one of the following concerning mid-ocean ridges is false?
A) They are sites for submarine eruptions of basaltic lava.
B) They are where young lithosphere is added to the edges of spreading, oceanic plates.
C) Terrigenous sediment coverings are very thin or absent.
D) Sediments include thick siliceous ooze deposits and sandy turbidite beds.
Q:
The crests of mid-oceanic ridges ________.
A) are heavily mantled with sediment
B) lie at depths exceeding 6 kilometers
C) contain active rift zones
D) are geologically old features
Q:
Which of the following is associated with ocean ridges?
A) rift zones
B) mountainous topography
C) volcanic structures
D) all of these
Q:
Abyssal plains are very flat because ________.
A) basalt volcanos on the seafloor produce little terrain
B) sediments accumulate to cover the seafloor topography
C) they have flat faults, the form flat, planar topography
D) they are not really flat; it is just that there is no data so they are shown as flat
Q:
If Yellowstone were on the ocean floor, it would produce ________.
A) a chain of line islands, like Hawaii
B) an island arc
C) a trench
D) a mid-ocean ridge
Q:
Deep sea trenches are important features for plate tectonic studies because ________.
A) they are sites where oceanic lithosphere is formed
B) they are sites where two plate move past each other horizontally
C) they are sites where the oceanic lithosphere is consumed into the mantle
D) none of the above
Q:
The ________ Ocean has more extensive abyssal plains than the Pacific Ocean because it has fewer trenches to trap sediments moving down the continental slope.
A) Indian
B) Atlantic
C) Arctic
D) none of these
Q:
Seamounts ________.
A) are a special type of oceanic trench
B) are volcanoes that form on the ocean floor
C) form only in the Pacific Ocean basin
D) are submarine canyons found near Australia
Q:
Which of the following is not true of deep ocean trenches?
A) They are long and narrow depressions.
B) They are sites where plates plunge back into the mantle.
C) They are geologically very stable.
D) They may act as sediment traps.
Q:
Subduction of oceanic lithosphere at the trenches can act like a bulldozer to produce ________.
A) subduction erosion
B) an accretionary wedge
C) a subduction slope
D) a strike slip fault like the San Andreas
Q:
Where are the deepest parts of the oceans?
A) along the base of the continental slope
B) in rift valleys at sea floor spreading center
C) in the abyssal plain
D) in trenches
Q:
What is the difference between an active continental margin and a passive continental margin?
A) A passive margin is the site of an ancient continental rift, left behind when seafloor spreading moved offshore, whereas an active margin is an active plate boundary.
B) A passive margin is passively carried along by plate tectonics in a transform system, like the San Andreas whereas an active margin is a trench.
C) An active margin receives large amounts of sediment whereas a passive margin is sediment starved.
D) An active margin has earthquakes whereas a passive margin has quiet erupting (aka passive) volcanos.
Q:
The continental rise is located ________.
A) at the top of a mid-ocean ridge
B) at the top of the continental slope
C) between an abyssal plain and continental slope
D) at the seaward edge of a deep ocean trench
Q:
________ develop where oceanic lithosphere bends downward and sinks into the mantle.
A) Submarine canyons
B) Abyssal seamounts
C) Deep ocean trenches
D) Rift valleys on mid-ocean ridges
Q:
The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the ________.
A) continental shelf
B) continental slope
C) continental rise
D) submarine canyon
Q:
In the Mississippi River delta in south Louisiana shallow subsurface imaging of the sediments reveal buried channels beneath delta sediments that are less than 10,000 years, and these channels extend offshore to the edge of the continental shelf. What is a simple explanation for these buried channels?
A) They represent giant flood events before the delta was formed and before the river formed.
B) They represent channels of the Mississippi river delta when sea level was lower, during the ice age.
C) The river must have been bigger in the past, cutting a channel clear to the edge of the shelf below sea level.
D) Turbidity currents cut a submarine canyon on the shelf before the delta buried them.
Q:
Submarine canyons found on the continental slope are believed to have been created ________.
A) by rivers during the ice age
B) by faulting
C) because of a plate plunging into the mantle
D) none of these