Exam 15: Ocean Basins

Where two oceanic plates converge, subduction generates huge amounts of magma that erupt to form submarine volcanoes, and eventually island arcs.

Deep, V-shaped, steep-walled valleys called __________ __________ are eroded into continental shelves and slopes.

Rift valleys are characterized by __________ faults and __________ earthquakes.

A chain of volcanic islands that form along a subduction zone is called a/an __________ __________.

Some of the world's richest offshore petroleum reserves are found on continental shelves.

Beyond the Mid-Oceanic Ridge system are flat, level, featureless submarine surfaces called __________ __________.

The west coast of South America is a passive continental margin.

Samples can be taken from the deep sea floor by:

A/an __________ __________ is a deep trough in the crest of many mid-ocean ridges.

The part of oceanic crust made up of pelagic and terrigenous sediment is:

Oceanic crust is mostly composed of __________.

The Mid-Oceanic Ridge system is the Earth's largest mountain chain.

The depth of the central parts of the ocean basins is about __________ kilometers.

At sea-floor vents, bacteria produce energy from hydrogen sulfide in a process called:

Moving away from mid-ocean ridges, oceanic crust becomes:

The continental rise on a passive continental margin is a/an:

Active continental margins do not have continental rises.

Oceans cover about __________ percent of the Earth's surface.

Hot seawater dissolves metals as it circulates through oceanic crust.

Submarine canyons on continental shelves and slopes are cut by __________.