Exam 11: The Ocean Floor

Active continental margins are found ________.

Except for the young volcanic mid-ocean ridges and active seamounts, most of the seafloor is mantled by sediments.

________ correctly formulated a basic theory concerning the formation of atolls in the 1800s.

The sequence of rocks that comprise an accretionary wedge is called an ophiolite.

The mid-ocean ridge system is typically 1000 to 4000 km wide but broken into discreet segments every few hundred kilometres by transform faults over most of its 70,000 km length.

In terms of distinctiveness in depth and ruggedness, the three different regions of the seafloor are: ________.

Jacques Picard was the first to postulate the process for the formation of atolls from the limited depth range of living corals.

Rift zones are narrow areas along the oceanic trenches where hot solid mantle rocks rise upward to replace the material that has shifted horizontally.

An atoll is a low, coral reef island typically surrounding an interior lagoon.

What is the most abundant sediment type on the deep ocean floor for most locations in the world?

The release of water and other volatiles from a subducting plate triggers melting in the overlying wedge of asthenosphere and gives rise to volcanic island arcs or mountain chains like the Andes.

Which of the following about deep ocean trenches is false?

The velocity of sound in ordinary seawater is about 1500 metres/second.

In the oceans, calcium carbonate is more soluble in warm, surface waters than in deeper, colder waters.

Other than providing shipping lanes and possible resources from placer mineral deposits name an important economic activity or resource from the continental shelves.

The East Pacific Rise is the most intensively studied seafloor spreading centre.

For its size, which ocean has the largest proportion of abyssal plains?

________ are highly detrimental to healthy growth of coral reefs.

What two transport paths or processes contribute most of the sediment to the ocean floor.

Which ocean floor sediment type includes turbidity currents?