Unit 3: Earth's Waters

How much of the earth's water is saltwater?

• 97%

• 3%

• 30%

• 70%

Freshwater is considered scarce because

• only about 3% of Earth's water is fresh and of that, 70% is frozen.

• 97% of Earth's water is fresh and of that, 70% is frozen

• only about 3% of water is fresh, of that 30% is frozen

The continuous movement of water through environment of the Earth is called:

• water recycling

• the water cycle

• condensation

• precipitation

An area of land in which water drains into a steam system which usually leads to an ocean is called

• divide

• drainage basin/watershed

• tributary

• river

What is lake turnover?

• rising and sinking of cold and warm water layers in a lake

• the layers of water, with the warmest on top and the coolest at the bottom

• the physical process by which people stir up lakes

• the rising of nutrients in a lake

In order for an aquifer to exist there must be

• a water source

• a semipermeable layer of rock or sediment

• an impermeable layer of rock or sediment

• a permeable layer of rock or sediment

The top of the area underground that is completely saturated with water is called

• saturation zone

• aquifer

• unsaturated zone

• water table

Discharge entering a stream at a specific, detectable point such as a pipe or outfall.

• Point source pollution

• Non-point source pollution

• Fog

• Riparian

Diffuse runoff from large areas of land.

• Point source pollution

• Nonpoint source pollution

• Sediment

• Watershed

Rapid, dense growth of algae that robs the water of oxygen as it dies and decomposes.

• Algal bloom

• Sediment

• Point source pollution

• Non-point source pollution