A technique that uses sound waves to measure the depth of the ocean floor is:

• dredging

• sonar

• SCUBA

• weighted lines

Which of the following features is made up of a range of mountains that wind through the ocean?

• seamount

• trench

• abyssal plain

• mid-ocean ridge

A nearly flat region of the ocean floor, covered with thick layers of sediment, is called a(an)

• seamount.

• abyssal plain.

• continental slope.

• mid-ocean ridge.

When a tsunami hits the shore, it can be very destructive because of its large

• sandbar.

• trough.

• wave height.

• frequency.

Salinity is a measure of which of the following in water?

• carbon dioxide

• phosphorus

• dissolved salts

• sand

As you descend through the water column,

• temperature decreases

• pressure decreases.

• light increases.

• density decreases.

A large stream of moving water that flows through the oceans is called a(an)

• current.

• tsunami.

• tide.

• undertow.

The atmosphere is

• the layer in which weather occurs.

• the layer that contains the ozone layer.

• the layer of water in the oceans.

• the layer of gases that surrounds Earth.

Earth’s atmosphere is important to living things because it

• contains dust and other particles.

• is very thin compared to the size of Earth.

• provides all the gases that living things need to survive.

• maintains a constant relative humidity.

Instruments used to measure air pressure are called

• thermometers.

• hygrometers.

• hydrometers.

• barometers.