Earth’s Waters

Chapter 1: The Water Planet

Section 1.1

Water Continuously Cycles

Water is a unique substance.

* Earth is the only planet with a large amount of liquid water.

* Because of water, Earth can support life.

* Water is the only substance on Earth that exists in all three physical states at normal temperature.

Water covers most of Earth.* Earth’s four

named oceans are all connected to form one huge ocean that covers 71 percent of the planet’s surface.

Continued

* ALL life is dependent on water.* The human body is two-thirds water.* Most rivers and lakes contain fresh

water, which is not salty and has little taste.

* The oceans contain salt water, which has many dissolved minerals.

* Most (97%) water on Earth is salt water.

Water moves in a worldwide

cycle.

Water on Earth is continuously moving from one place and form to another. This continuous movement is called the water cycle.

1

2 3

1Condensation:Vapor changes into liquid.

2

Precipitation: Water falls to the surface.

3

Evaporation: Water rises as vapor.

Continued

* The water cycle involves three processes.•Evaporation: water changes from

a liquid to a gas (vapor).•Condensation: Water changes

from a gas (vapor) to a liquid.•Precipitation: any form of water

that falls from clouds after condensation has taken place.

Continued

* The water cycle impacts our lives through precipitation, which brings needed fresh water for drinking and crops but may also cause flooding or other problems.

Section 1.2 Fresh Water Flows and

Freezes on Earth

Water flows and collects on Earth’s

surface.* The force of gravity pulls water

downward. * When precipitation falls on a high

ridge that forms a divide, it flows away in different directions.

* All the water flowing downward on one side of a divide flows into a drainage basin.

Continued* Water in a drainage basin forms streams

and rivers or sinks into the ground. Most water eventually flows to the sea. Much of Earth’s fresh water is frozen.

Surface water collects in ponds and lakes.

* Water collects in low areas to form ponds and lakes.

* Water enters as precipitation or run off from streams.

* Lake = larger than pond, can’t usually see the bottom (deep).

* Pond = smaller than lake, usually filled with plants.

* Turnover = during winter, the cool water layers switch places with the warm layers

Continued

* Turnover = during winter, the cool water layers switch places with the warm layers.

Continued

* Eutrophication•An increase of nutrient level in a lake

or pond.•Caused by buildup of deadly organisms

or by pollution such as fertilizers and phosphates from detergents.

•Causes increase in algae in water which causes oxygen depletion in water, then the plants and animals die.

Eutrophication

Continued

* Cleveland, Wisconsin: Knee-deep algae closed down the boat landing in Lake Michigan (2002).

Most fresh water on Earth is frozen.* 2/3 Earth’s water

is frozen near the poles in continental glaciers.

* Valley glaciers build up in mountainous areas and flow slowly down between the mountains.

Continued

* An Iceberg is a piece of glacier that breaks off and floats in the ocean. Only about 1/8 of the total volume and weight of an iceberg floats above the water.

Section 1.3

Fresh Water Flows Underground

Water fills underground spaces.

* Some water sinks into the ground.• Plants use some of

it.• Some sinks deeper

into Earth and is held underground as groundwater.

• Wells draw water from the aquifer.

Continued* Water collects and moves beneath

the land surface.

Continued

* Either ground materials are:•Permeable: water can flow

through them. (sandstone, sand, gravel, soil)

• Impermeable: water can not flow through them. (water table)

* Water continues to sink until it reaches an impermeable layer.

* The water table is the top of the area that is saturated with water.

Continued

* Aquifer: An underground layer of permeable rock or sediment that contains water .•Ground water is stored here.•Located over or beside

impermeable rock .•The water is constantly

replenished.•Aquifers filter and clean water.•Provide fresh water source.

Continued

Underground water can be brought to the

surface.* People collect water from wells and

springs.* Spring: where the surface of the land

dips below the water table and water bubbles up from underground.

* Technology is helpful in dry and remote regions.

* Well: a hole drilled into the ground to reach groundwater.

Continued

See page 29.

Continued * Artesian Well: water flows to the surface naturally because of pressure exerted below the surface.

* Hot Spring: a place where heated water reaches the surface.

Continued

* Geyser: special kind of hot spring.

Underground water is heated and “plumbed”

upward.

Hot water and steam are pushed to the surface

where they erupt.