OCE Chapter 3
Due to the very harsh environmental conditions, very few types of organisms are found in association with hydrothermal vents.
False
Ocean trenches are deep linear scars in the ocean floor caused by the divergence of plates along divergent plate boundaries.
False
Seamounts form from ancient tablemounts.
False
The continental shelf is generally defined as a steeply sloping zone extending from the shoreline to the shelf break.
False
The deepest portions of the ocean are part of the relatively narrow features called submarine canyons.
False
The three major provinces of the ocean floor are continental margins, deep-ocean basins, and submarine canyons.
False
Satellites measurements of the ocean surface can be used to make maps of the seafloor.
True
Sediments of the continental rise can exhibit characteristics similar to those formed by rivers on land.
True
Continental shelf
a flat, gently sloping zone extending from the beneath the ocean surface to the point at which a marked increase in slope occurs (shelf break)
continental shelf
a generally flat zone extending from the shore to the shelf break
multi-beam sonar
a method of mapping the topography of the ocean floor along a strip up to 60 km
Submarine canyon
a narrow, deep submarine valleys that are V-shaped in profile and have branches with steep to overhanging walls found on the continental shelf
Continental rise
a transition zone between the continental margin and the deep ocean floor composed of huge submerged pile of sediments
Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called:
abyssal plains.
ocean trench
deep linear scars on the deep-ocean floor caused by plate convergence
What are turbidity currents?
dense mixtures of sand, mud, and other debris that move at high speeds down submarine canyons
What process(es) is/are involved in the formation of continental shelves?
deposition by waves
Deep sea fan
deposits at the mouth of submarine canyons; create the continental rise when the merge along the base of the continental slope
Oceanic ridges and rises result from seafloor spreading along:
divergent plate boundaries.
abyssal plain
flat depositional surfaces that cover extensive portions of the deep-ocean basins
The direction of motion along a seafloor transform fault is:
in the same direction as the plates are spreading.
How often do turbidity currents occur?
infrequently
Continental slope
lies beyond the shelf break, with a steeper incline, extending out to the deep ocean basin
Segments of the oceanic ridge system that are gentler and less rugged in slope due to faster rates of seafloor spreading are called:
oceanic rises.
Along the margins of the Pacific are found most of Earth's:
oceanic trenches.
Most ocean floor features owe their origins to _________.
plate tectonic processes
Volcanic peaks on the deep-ocean floor with conical tops are called:
seamounts
Underwater avalanches of muddy water mixed with rocks and debris are:
turbidity currents.
precision-depth recorder (PDR)
uses high frequency sound waves to measure ocean depth
Nearly all oceanic islands are __________.
volcanic in origin
Of the following statements about Earth's hypsographic curve which is true?
The hypsographic curve shows the percentage of Earth's surface area that is covered by ocean waters.
Black smokers are hydrothermal vents that discharge superheated water with high concentrations of metal sulfides.
True
Oceanic ridges are cut by a number of transform faults, which offset spreading zones.
True
The two relatively flat areas on the hypsographic curve represent:
some interior continental areas/coastal plains and abyssal plains on the ocean floor.
The method that used most frequently to investigate sediment and rock layers of the sea floor is:
sound waves (specifically seismic reflecting profiling).
