Oceans

Front

A measure of the amount of dissolved salt contained in water

Back

Salinity

Front

A very large expanse of sea, in particular, each of the main areas into which the sea is divided geographically

Back

Oceans

Front

A system that uses sound waves to measure distances and locate objects.

Back

Sonar

Front

Underwater mountains

Back

Seamounts

Front

A wide flat area of the ocean floor that is covered with a thick layer of sediment

Back

Abyssal Plain

Front

Underwater volcanoes tall enough to reach above the surface

Back

Volcanic Island

Front

The flat or gradually sloping land that extends underwater from the edge of a continent to a continental slope

Back

Continental Shelf

Front

land that drops down steeply at the edge of a continental shelf

Back

Continental slope

Front

all natural and human-made surface features of a particular area

Back

Topography

Front

narrow steep sided clefts in the ocean floor

Back

Ocean trenches