The Ocean Floor - Final Review Flashcards
An echo sounder operates by measuring the time required for a ________.
sound pulse to travel from a ship to the seafloor and back
Geologically, ________ are actually submerged parts of the continents.
continental shelves
The ________ lies at the base of the continental slope.
continental rise
The gently sloping submerged surface extending from the shoreline toward the ocean is termed the ________.
continental shelf
________ is the oceanward edge of a continental shelf.
The top of the continental slope
Oceans cover approximately ________ of Earth’s surface area?
70%
Which of the following is NOT true of deep ocean trenches?
They are geologically very stable.
Seamounts ________.
are volcanoes that form on the ocean floor
________ are not associated with a mid-ocean ridge.
Deep ocean trenches
Where in the oceans are biological communities thriving without sunlight?
around seafloor, hot spring vents
Which plate does not contain significant areas of continental landmass?
Pacific plate
Which feature of mid-ocean ridge is absent when the spreading rate is fast along a divergent plate boundary?
Rift valley
What changes have occurred to Farallon plate since 56 million years ago?
It has subducted into mantle and got smaller and smaller
What is the most top layer of ophiolite complex of the oceanic crust?
Deep sea sediments
True or False?
The west coast of South America and the east coast of North America have very different continental margins.
True
True or False?
Submerged, flat-topped seamounts are known as guyots.
True
True or False?
The Atlantic and Pacific basins have oceanic ridges; the Indian Ocean has no oceanic ridge.
False
True or False?
Passive continental margins typically exhibit wide, extensive, continental shelves.
True
True or False?
A passive continental margin marks the site where old, oceanic lithosphere begins its descent into a subduction zone.
False
True or False?
Seawater circulates downward through the highly fractured oceanic crust
True
True or False?
There is no faulting along mid ocean ridge system.
False
True or False?
Abyssal plains are likely the most leveled places on Earth.
True
True or False?
Deep ocean trenches are considered the deepest part of the oceans.
True
Order of ocean floor features
Continental Shelf Continental Slope Continental Rise Abyssal Plain Mid-Ocean Ridge
