Oceanography chap 4-5
What marks the true division between continents and oceans? Abyssal plains Coastlines Coastal deep-sea trenches Granite-basalt transitions Alluvial fans
Granite-basalt transitions
What is the most likely rock to be found in a drill core of a continental margin? Granite Carbonate Alluvial rock Basalt Shell
Granite
Why is the average sediment thickness in the Pacific Ocean less than that of the Atlantic Ocean? The Pacific is smaller in area than the Atlantic. Ocean trenches trap sediments. More rivers feed into the Pacific. Lithification occurs more frequently in the Pacific. More areas of the Pacific have experienced glaciation.
Ocean trenches trap sediments.
deep-water open water (200-1000 m deep) zone bathypelagic inner sublittoral oceanic mesopelagic neritic
mesopelagic
Near shore open water zone. bathypelagic inner sublittoral oceanic mesopelagic neritic
neritic
Deep-water open water zone beyond the continental shelf bathypelagic inner sublittoral oceanic mesopelagic neritic
oceanic
Weight of ice on Antarctica has isostatically depressed the continent, and thereby increased the depth of water at the shelf break. True False
true
Which particle size is transported the farthest by waves and currents? silt clay pebble cobble sand
Clay
What characteristic of continental crust accounts for more than half of Earth's solid surface being below sea level? Continental crust is denser than oceanic crust. Continental crust is thinner than oceanic crust. Continental crust is less dense than oceanic crust. Continental crust is both less dense and thinner than oceanic crust. Continental crust is the same density and thickness as oceanic crust
Continental crust is less dense than oceanic crust.
Hydrothermal vents are only found in seawater. True False
False
Neritic sediments are mainly comprised of biogenous sediments due to the proximity to the continental shelf. True False
False
Oceanic crust contains a higher percentage of oceanic ridges than ocean basin floors. True False
False
The epipelagic zone corresponds to the deep aphotic depths where light does not reach. True False
False
The mix of rubble at the base of a rapidly eroding shore cliff is an example of a well-sorted sediment. True False
False
The silica from the shells of diatoms dissolves at a faster rate than the calcium carbonate of foraminifera shells. True False
False
The water temperature at the bottom of ocean trenches is very warm. True False
False
What accounts for the offsets that occurs along the mid-ocean ridge lines? Faults Abyssal plains Subduction zones Seamounts Abyssal hills
Faults
Deep-ocean sediments are typically composed of ____. Beach sand Silt Shells Biological oozes Fine clays
Fine clays
What feature distinguishes a guyot from a seamount? Flat top Forms at spreading centers Moves with the seafloor Steep sides Rises above sea level
Flat top
_____ are seismically inactive areas of oceanic ridges that show evidence of past transform fault activity. Seamounts Hydrothermal vents Fracture zones Abyssal plains Abyssal hills
Fracture zones
Where is the deepest region in the ocean? Aleutian Trench East Pacific Rise Mid-Atlantic Ridge Peru-Chile Trench Mariana Trench
Mariana Trench
Which areas of the ocean is most likely to have the least accumulation of sediment? Abyssal plain Continental shelf Continental slope Deep-sea trench Oceanic ridge
Oceanic ridge
What features of ocean basins are chains of basaltic rock that stretch more than 1.5 times Earth's circumference around the world at spreading centers? Abyssal plains Abyssal hills Seamounts Oceanic ridges Island arcs
Oceanic ridges
A poorly-sorted sediment would most likely be found in a(n) _____. lake bed eroding shore cliff deep-ocean basin oceanic ridge abyssal plain
eroding shore cliff
Active margins typically are located in the Atlantic Ocean. True False
false
Continental crust is both thicker and denser than oceanic lithosphere. True False
false
Segments of a lithospheric plate on either side of a transform fault move in the same direction as one another. True False
false
Spreading centers at the Mid-Atlantic Ridge spread at a faster rate than those at the East Pacific Rise. True False
false
The Gulf of Mexico is located at an active margin. True False
false
The deepest part of the ocean is in the Pacific's Peru-Chile Trench. True False
false
cosmogenous sediment glassy nodule quartz-sand ooze manganese nodule silt
glassy nodule
Sediments that are gray in color tend to be ____. biological in origin oxidized high in iron high in silica high in manganese
high in silica
ocean bottom near shore zone bathypelagic inner sublittoral oceanic mesopelagic neritic
inner sublittoral
authigenic sediment glassy nodule quartz-sand ooze manganese nodule silt
manganese nodule
Which is classified as cosmogenous sediment? evaporites ooliths microtektites manganese nodules siliceous ooze
microtektites
Hydrothermal vents typically form chimneys of _____. basaltic rock granitic rock carbonate mineral deposits sediments
mineral deposits
Approximately how much of the world's estimated oil and gas reserves are deposited within the sediments of continental margins? one-third one-half two-thirds three-quarters one-fourth
one-third
biogenous sediment glassy nodule quartz-sand ooze manganese nodule silt
ooze
Abyssal plains are relatively rare in the Pacific Ocean. True False
True
Manganese nodules can grow to exceed 1 meter in diameter within about 100 years. True False
False
Manganese nodules have successfully been commercially mined in the ocean. True False
False
The rate of sediment deposition is fairly consistent throughout the ocean. True False
False
What region of a continental margin blends into the deep-ocean basin? Continental slope Continental shelf Continental basin Continental rise Continental plain
Continental rise
What zone is represented by sediment and water from the bottom of the deep ocean? Pelagic Neritic Oceanic Benthic Subpelagic
Benthic
What zone is classified by its location in the open water? Benthic zone Pelagic zone Bathyl zone Abyssal zone Littoral zone
Pelagic zone
What is an example of authigenic sediment? Quartz sand Phosphorite deposits Volcanic dust Diatomaceous ooze Tektite spheres
Phosphorite deposits
What is the most likely source of sediment collected from an abyssal plain? Biological activity in ocean Terrestrial Magma Mineral deposits at vents Spreading centers
Terrestrial
The ____ comprise the highest percent of ocean area, but contain the lowest percent sediment volume. continental shelves continental slopes deep-ocean floor continental rises submarine canyons
deep-ocean floor
What type of deep ocean sediment is most common in the deep-ocean basins surrounding Antarctic? authigenic deposits diatom ooze calcareous ooze turbidic deposits hydrogenous deposits
diatom ooze
Deep-sea drilling helped to give rise to the science of _____. paleoceanography geological oceanography physical oceanography marine geology sedimentary oceanography
paleoceanography
Sediments of the slope, rise, and deep ocean floor that originate in the ocean are called ____. neritic sediments pelagic sediments terrigenous sediments well-sorted sediments authigenic sediments
pelagic sediments
It is estimated to take _____ for the ocean's volume to circulate through the oceanic crust at spreading centers. 1 million years 10 million years 100 million years 1 billion years 10 billion years
10 million years
_____ lie between the continental margins and the oceanic ridges. Spreading centers Shelves Slopes Abyssal plains Rises
Abyssal plains
What is the best-known and oldest deep-diving manned research submersible now in operation? Trieste Jiaolong Challenger Alvin Shinkai
Alvin
Where are abyssal plains most common? Atlantic Ocean Indian Ocean Southern Ocean Pacific Ocean Arctic Ocean
Atlantic Ocean
Passive margins are also referred to as ____. Converging-type margins Pacific-type margins Atlantic-type margins Basin-type margins Inactive-type margins
Atlantic-type margins
What is a typical characteristic of passive margins? Volcanic activity Coincide with plate boundaries Narrow continental shelf Broad continental shelf Deep trenches
Broad continental shelf
What occurs below the calcium carbonate compensation depth? Calcium carbonate begins to precipitate into a solid. Calcium carbonate begins to dissolve. The rate of calcareous sediment accumulation is greater than the rate of dissolution. Seawater becomes less acidic. Calcareous oozes start to form.
Calcium carbonate begins to dissolve.
What is an important factor in shaping the sediments of the continental rise? Earthquakes Deep ocean currents Shelf breaks Sea level changes Subduction
Deep ocean currents
How is the surface water above a deep trench in the ocean floor distorted as a result of the trench? Downward distortion Upward distortion Sideways distortion Vortex distortion No distortion
Downward distortion
Where was the first hydrothermal vent discovered? Mid-Atlantic Ridge East Pacific Rise Gulf of Mexico Sea of Cortez Juan de Fuca Ridge
East Pacific Rise
What instrument used during the early part of the twentieth century improved the accuracy of ocean depth measurements compared to the rope and weight? Remotely operated underwater vehicle Acoustic Doppler current profiler Satellite Autonomous underwater vehicle Echo sounder
Echo sounder
Biological sediments are the most abundant sediments in total volume in the ocean due to the high productivity of organisms along the continental shelf. True False
False
Calcareous oozes are common at deep-ocean depths below 4,500 m. True False
False
What do satellites measure that provides data for seafloor topographical mapping? "Pings" reflected from seabed Sea surface height Sound pulses from ships Seawater density Wave energy
Sea surface height
What explorer's expeditions used rope with a weight attached to determine ocean depths? Eratosthenes Ferdinand Magellan Sir James Clark Ross Christopher Columbus James Cook
Sir James Clark Ross
What process gives trenches their unique arc-shaped depressions? Spreading Volcanic eruptions Subduction Turbidity Erosion
Subduction
What geological feature is often found at active margins? Alluvial plain Subduction zone Salt dome High sedimentation Broad shelves
Subduction zone
What is a characteristic of Earth's oceans? The height of Mt. Everest is greater than the depth of the deepest ocean trench. Alluvial fans make up a large portion of ocean basins. An ocean basin is shaped like a giant bathtub. Abyssal plains are located within continental margins. The average ocean depth is greater than the average elevation of continents.
The average ocean depth is greater than the average elevation of continents.
_____ faults are most typically found at spreading centers. Strike-slip Transform Normal Reverse Oblique
Transform
Clays can remain suspended in the water column for decades before settling due to their small size. True False
True
Lithification is a pressure-induced process. True False
True
Past sea surface temperatures can be determined from fossils found in deep ocean sediments. True False
True
The compression of small biological particles into fecal pellets increases the rate at which they sink to the bottom of the ocean. True False
True
Multibeam echo sounders radiate multiple beams of sound pulses to give a larger coverage pattern on ocean floors compared to the original single echo sounders. True False
True
Neritic sediments are mostly eroded from land. True False
True
Sediment in deep-ocean basins can be up to 5 kilometers (3 miles) thick. True False
True
Sediment on the continental slopes has an average thickness that is greater than sediment on the continental shelves. True False
True
Sediments of white or cream color tend to be of biological origin. True False
True
Most geologists believe that submarine canyons have been formed by ____. Stream erosion Subduction Volcanoes Sea level changes Turbidity currents
Turbidity currents
deep-water open water (1000-4000 m deep) zone bathypelagic inner sublittoral oceanic mesopelagic neritic
bathhypelagic
The west coast of South America is known for its seasonal upwelling. What kind of sediment is likely to be abundant in this area? terrigenous hydrogenous biogenous cosmogenous authigenic
biogenous
What is the particle size distribution from largest to smallest? cobble -boulder -granule -pebble coarse silt -granule -fine silt -clay coarse sand -granule -medium sand -fine sand boulder -granule -coarse sand -coarse silt cobble -granule -pebble- coarse sand
boulder -granule -coarse sand -coarse silt
An abundance of foraminifera shells would be described as what type of sediment? turbidic sediment calcareous ooze siliceous ooze evaporitic sediment diatomaceous earth
calcareous ooze
Which is an example of an evaporite? manganese nodule phosphorite oolite calcium carbonate tektite
calcium carbonate
Which particle size has the fastest settling velocity in still water? clay fine sand coarse sand silt coarse silt
coarse sand
The White Cliffs of Dover in England were formed as a result of which marine organism? oolite diatom radiolarian turbidite coccolithophore
coccolithophore
Which oceanographic sampling device played a large role in verifying the plate tectonic theory? boxcore sampler clamshell sampler piston corer seismic profiler acoustic Doppler profiler
piston corer
An area that experiences a high rate of erosion, such as a near shore cliff, will have which type of sediments in the surrounding waters? well-sorted sediments poorly-sorted sediments one size of sediment mostly gravel sediment mostly clay sediment
poorly-sorted sediments
coarse terrigenous sediment glassy nodule quartz-sand ooze manganese nodule silt
quartz sand
What is the main source of terrigenous sediments to the ocean? volcanic eruptions rivers dust and ash cosmic dust marine snow
rivers
Most marine sediments are composed of what size of particles? boulders sand, silt, and clay cobbles pebbles cobbles or granules
sand, silt, and clay
Mud-sized sediment glassy nodule quartz-sand ooze manganese nodule silt
silt
Which geological processes explains why the ocean floors are so young? sea floor spreading subduction volcanic activity rift formation mountain formation
subduction
What is the primary origin of most neritic sediments? calcareous terrigenous hydrogenous cosmogenous
terrigenous
What is the most abundant marine sediment in total volume? cosmogenous authigenic biogenous hydrogenous terrigenous
terrigenous
What type of marine sediment is derived from igneous rock? terrigenous biogenous hydrogenous cosmogenous calcareous
terrigenous
Robots can be used in the ocean to measure water salinity. True False
true
Which deposits are the result of gravity-propelled currents that produce graded layers of sediment deposits? oozes lithified nodules tektites oolites turbidites
turbidites
Which statement is true of sediments in the ocean? Biogenous sediments comprise a larger area than terrigenous sediments. Terrigenous sediments comprise a larger area than biogenous sediments. Hydrogenous sediments cover more volume than biogenous sediments. Cosmogenous sediments cover more volume than biogenous sediments. Terrigenous and biogenous sediments are equal in area and volume.
Biogenous sediments comprise a larger area than terrigenous sediments.