Chapter 3 Flashcards
Satellites are used to map the ocean floor because _______.
Gravitational bulges in sea surface
The two relatively flat areas on the hypsographic curve represent ____.
Abyssal plain, continental shelf
The correct order of seafloor features from the coast to the mid-ocean ridge is _______.
Continental shelf, continental slope, continental rise, abyssal plane
Active continental margins are characterized by which of the following?
Convergent/transform boundaries, ocean trench, seamounts
Characteristics of passive continental margins include which of the following?
Broad continental shelves
Which of the following features is related to transform faults along mid-ocean ridges?
Fracture zones
Directly seaward of the continental shelf is a more steeply sloping region called the ______.
Shelf break
Underwater avalanches of muddy water mixed with rocks and debris are _______.
Turbidity currents
Submarine canyons were most likely formed by _______.
Turbidity currents
Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called ______.
Abyssal plains
Relatively few abyssal plains are located in the Pacific ocean due to ______.
The presence of convergent active margins
Volcanic peaks on the deep-ocean floor with conical tops are called:
Seamounts
Along the margins of the Pacific are found most of Earth’s ___.
Earthquakes/volcanoes
Older lithosphere is destroyed in association with:
Deep sea trenches
Oceanic ridges and rises result from seafloor spreading along ______.
Divergent plate boundaries
New lithosphere is produced in association with ____.
Oceanic ridges
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
The direction of motion along a seafloor transform fault is ______.
In the same direction that the plates are spreading
With respect to mid-ocean ridges, transform faults are _______.
Perpendicular to the ridge axis
Seamounts and abyssal hills are _____ in origin.
Volcanic
Volcanic peaks that are below sea level but rise more than 1 kilometer above the deep-ocean floor and have a pointy top like an upside-down ice cream cone are called ______.
Seamounts
Volcanic peaks that are below sea level but rise more than 1 kilometer above the deep-ocean floor and have a flattened top are called ______.
Tablemounts
Volcanic features on the ocean floor that are less than 1000 meters tall are called:
Seaknolls (abyssal hills)
What percent of Earth’s volcanic activity, each year, takes place on the seafloor?
80%
The Big Island of Hawaii is an example of a volcanic island associated with volcanic activity at a _______.
Hotspot
Which of the following is an example of a passive continental margin?
Atlantic
Passive margins are usually produced over geologic time by which of the following?
Continental rifting and continued seafloor spreading
The average slope of the continental shelf is approximately _____.
A 10th of a degree
The average slope of the continental shelf is similar to the slope of which of the following?
Parking lot
Where does the deep-ocean basin begin along a passive continental margin?
Continental slope
Deep-ocean trenches and volcanic arcs result from the collision of two plates at convergent plate boundaries and mostly occur along the margins of which of the following oceans?
Pacific ocean
Where are the deepest portions of the world’s oceans found?
At convergent plate boundaries
Oceanic ridges and rises result from seafloor spreading along _______.
Divergent plate boundaries
Along the margins of the Pacific are found most of Earth’s _____.
Oceanic trenches
