Quiz 18: The Sea Floor
Geology/Geography/Oceanography/Atmospheric Sciences
Free
True False
False
Free
True False
True
Free
True False
True
Free
True False
Q 5Q 5
The ocean became salty as water picked up chlorine from volcanic gases and sodium and magnesium from weathering of minerals at the Earth's surface.
Free
True False
Q 6Q 6
Ophiolitic sediment is composed of wind-blown dust and microscopic skeletons that settle slowly to the sea floor.
Free
True False
Free
True False
Q 8Q 8
The continental rise is a wedge of sediment that extends from the lower part of the continent slope to the deep-sea floor.
Free
True False
Free
True False
Free
True False
Free
True False
Free
True False
Free
True False
Free
True False
Free
True False
Q 16Q 16
Passive margins are found on the edges of most of the landmasses bordering the Pacific Ocean.
Free
True False
Free
True False
Free
True False
Q 19Q 19
A contour current is a bottom current that flows parallel to the slopes of the continental margin.
Free
True False
Free
True False
Q 21Q 21
The study of _____ rocks, sediment, and topography provided most of the information that led to the concept of plate tectonics.
A) seafloor
B) ocean boundaries containing
C) continental interior
D) mid-oceanic ridge
E) abyssal plains
Free
Multiple Choice
Q 22Q 22
These machines can take geologists to many parts of the sea floor to observe, photograph, and sample rock and sediment.
A) deep sea drilling platforms
B) submersibles
C) sonar
D) echo sounder
E) multibeam sonar
Free
Multiple Choice
Q 23Q 23
This instrument works on essentially the same principles as echo sounder but can penetrate the bottom of the sea floor and provides more information.
A) multibeam sonar
B) single beam sonar
C) seismic refraction profiler
D) seismic reflection profiler
E) sonar profiler
Free
Multiple Choice
Q 24Q 24
Abyssal fans are made up of _____ sediment that has moved down submarine canyons
A) abyssal
B) continental slope
C) deep sea
D) marine pelagic
E) land-derived
Free
Multiple Choice
Q 25Q 25
Turbidity currents are great masses of sediment-laden water that are pulled downhill by ____.
A) landslides
B) submarine canyons
C) gravity
D) earthquakes, storms, volcanic eruptions
E) Earth's rotation
Free
Multiple Choice
Q 26Q 26
_____ currents are bottom currents that flows parallel to the slopes of the continental margin.
A) Turbidity
B) Gulf Stream
C) Newfoundland
D) Contour
E) Abyssal
Free
Multiple Choice
Q 27Q 27
A(n) _____ continental margin usually lacks a continental rise and an abyssal plain and is associated with convergent plate boundaries.
A) active
B) passive
C) transform
D) subducting
E) remote
Free
Multiple Choice
Q 28Q 28
Earthquakes, volcanoes, Benioff seismic zones, and island arcs are all associated with this sea floor feature.
A) guyots
B) passive margin
C) seamounts
D) oceanic trench
E) abyssal plains
Free
Multiple Choice
Q 29Q 29
Mid-oceanic ridges are often marked by lines of _____ that carry and precipitate metals.
A) ocean currents
B) hot springs
C) seismic ridges
D) submarine volcanoes
E) ocean trenches
Free
Multiple Choice
Q 30Q 30
_____ are major lines of weakness in Earth's crust that cross the mid-oceanic ridge at right angles.
A) Abyssal fans
B) Fracture zones
C) Submarine canyons
D) Transform faults
E) Fold belts
Free
Multiple Choice
Q 31Q 31
Geologists' ideas about the composition of ocean crust are greatly influenced by the study of ____.
A) ophiolites
B) continental volcanoes
C) chert
D) the Mohorovicic discontinuity
E) the asthenosphere
Free
Multiple Choice
Q 32Q 32
The ____ is a shallow submarine platform at the edge of a continent.
A) abyssal plain
B) continental shelf
C) aseismic ridge
D) rise
E) trench
Free
Multiple Choice
Q 33Q 33
A(n) _____ is a great mass of sediment-laden water that is pulled downward by gravity along the continental slope.
A) avalanche
B) underwater landslide
C) turbidity flow
D) mudflow
E) gravity slide
Free
Multiple Choice
Q 34Q 34
Turbidity currents flow down the continental slope until they come to rest on ___.
A) the continental shelf
B) the mid-oceanic ridge
C) a guyot
D) the abyssal plain
E) a submarine trench
Free
Multiple Choice
Q 35Q 35
Shallow focus earthquakes on the sea floor are associated with ___.
A) trenches
B) abyssal rises
C) guyots
D) abyssal plains
E) mid-ocean ridge crests
Free
Multiple Choice
Q 36Q 36
The _____ crust of the sea floor is covered in many places with layers of sediment.
A) basalt
B) granite
C) rhyolite
D) serpentine
E) andesite
Free
Multiple Choice
Q 37Q 37
Most geologists think that the flat summits of seamounts ___.
A) are uplifted sea floor
B) were eroded flat by wave action
C) are fault surfaces
D) are remnants of the continental shelf
E) are remnants of plateau basalts
Free
Multiple Choice
Q 38Q 38
The crests of mid-oceanic ridges are associated with ____.
A) pelagic sediments
B) barrier reefs
C) rift valleys
D) abyssal plains
E) Benioff zones
Free
Multiple Choice
Q 39Q 39
A basic tool for indirectly studying the sea floor is the ____, which measures water depth.
A) drilling ship
B) rock dredge
C) submersible
D) echo sounder
E) gravimeter
Free
Multiple Choice
Q 40Q 40
Water depth increases over a continental shelf to the outer edge depth of _____ to ____ meters.
A) 500; 600
B) 400; 500
C) 300; 400
D) 200; 300
E) 100; 200
Free
Multiple Choice
Q 41Q 41
Seismic surveys of the sea have shown the oceanic crust to be divided into _______ major layers.
A) 3
B) 6
C) 5
D) 2
E) 7
Free
Multiple Choice
Q 42Q 42
Many guyots and seamounts are aligned in chains (for example the Hawaiian Islands and Emperor seamounts) that form major _____.
A) trench systems
B) aseismic ridges
C) Benioff zones
D) mid-ocean ridges
E) continental rises
Free
Multiple Choice
Q 43Q 43
_____ are rounded masses of rock that form when molten lava erupts into cold water.
A) Gabbro mountains
B) Sheeted dikes
C) Pillow lava
D) Dunite dikes
E) Columnar basalts
Free
Multiple Choice
Q 44Q 44
A ______ is a bottom flowing current that flows parallel to the slopes of the continental margins.
A) density flow
B) surface current
C) turbidity current
D) contour current
E) coriolis current
Free
Multiple Choice
Q 45Q 45
_______ is an island on a mid-oceanic ridge.
A) Madagascar
B) Japan
C) Cuba
D) Hawaii
E) Iceland
Free
Multiple Choice
Q 46Q 46
Most seamounts are ______.
A) extinct volcanoes
B) granitic intrusions
C) submerged reefs
D) fault block grabens
E) ophiolites
Free
Multiple Choice
Q 47Q 47
Project FAMOUS used submersibles to study ______.
A) trenches
B) mid-ocean ridges
C) guyots
D) reefs
E) continental rises
Free
Multiple Choice
Q 48Q 48
In a passive continental margin, there is a lack of _______.
A) seamounts
B) guyots
C) earthquakes, volcanoes, and young mountain belts
D) no riverine discharge
E) sediments
Free
Multiple Choice
Q 49Q 49
The abyssal plains are formed of _____.
A) sediment from meteoric dust
B) pillow basalts
C) mid-oceanic ridges
D) horizontal layers of sediment
E) volcanic ash
Free
Multiple Choice
Q 50Q 50
Oceanic trenches are marked by _______.
A) no seismicity
B) shallow depths
C) positive gravity anomalies
D) high heat flow
E) low heat flow
Free
Multiple Choice
Free
Multiple Choice
Q 52Q 52
Thick deposits of sediment called _____ are found at the base of many submarine canyons.
A) abyssal fans
B) continental rises
C) continental slopes
D) continental shelves
E) guyots
Free
Multiple Choice
Q 53Q 53
The Grand Banks cable breaks of 1929 are interpreted to be the result of earthquake-caused ____.
A) earthquakes
B) contour currents
C) tsunamis
D) underwater volcanic eruptions
E) turbidity currents
Free
Multiple Choice
Q 54Q 54
The continental rise typically ends at a(n) _______ at a depth of about 5 kilometers.
A) slope
B) trench
C) abyssal plain
D) mid-oceanic ridge
E) continental slope
Free
Multiple Choice
Q 55Q 55
The continental shelves of the world are typically covered by relatively young sediments derived from ___________.
A) contour currents
B) mid-oceanic ridges
C) turbidity currents
D) land
E) continental shelves
Free
Multiple Choice
Q 56Q 56
_____ are V-shaped valleys that run across continental shelves and down continental slopes.
A) Rift valleys
B) Submarine canyons
C) Submarine trenches
D) Guyots
E) Fracture zones
Free
Multiple Choice
Q 57Q 57
__________ is the name applied to hot springs on the seafloor where 350 degree Celsius metal-rich solutions are discharged into the cold waters of the ocean.
A) Black smokers
B) Fumaroles
C) Ophiolites
D) Andesite
E) Hot spots
Free
Multiple Choice
Q 58Q 58
The continental shelf is part of the ____.
A) abyssal plain
B) continents
C) mid-oceanic ridge
D) island arc system
E) true ocean basin
Free
Multiple Choice
Q 59Q 59
______ proposed that the three types of coral reefs are related to each other by subsidence of a central volcanic island.
A) Isaac Newton
B) Charles Plummer
C) George Bush
D) Charles Darwin
E) Diane Carlson
Free
Multiple Choice
Q 60Q 60
_____ parallel the shore, but are separated from it by wide, deep lagoons.
A) Barrier reefs
B) Atolls
C) Patch reefs
D) Guyot reefs
E) Fringing reefs
Free
Multiple Choice