Water Systems on Earth’s Surface:

Distribution of Water on Earth

Earth’s Water

Only 3% of the Earth’s water is fresh water (no salt).

2/3 of this water is frozen in ice sheets.

Therefore only 1% of the fresh water on Earth is available.

How Does the Earth not run out of Fresh water??

The Water Cycle....

The Water Cycle The constant cycling of water through the

processes of evaporation and condensation

Water is constantly changing form

(gas liquid)

Driven by the sun’s energy

Label the Water Cycle

The water cycle is a constant interaction between the hydrosphere, lithosphere and atmosphere.

Lithosphere: the solid rocky ground of the Earth’s crust.

Atmosphere: the environment surrounding the Earth.

Hydrosphere: All water on Earth. Including that in the lithosphere and atmosphere.

This includes: condensation in the air and clouds, run-off, and ground water

Journal Question Sketch and label the water cycle. Include definitions

for each label and the definitions for hydrosphere, lithosphere, and atmosphere.

Problems: Page 13

#”s: 1, 2, 3, 6, 7

Scientist Who Study Water Hydrologist: A person who studies Earth’s water

systems and helps to find solutions to problems of water quality and quantity.

Oceanographer: A person who studies all aspects of the ocean. They are concerned with the biology, geology, physics and mathematics of the ocean.

Ocean Water v.s. Fresh Water 3 ways in which ocean and fresh water differ:

Salinity

The amount of salt dissolved in a specific amount of water.

Salt comes from dissolved solids in the ground and volcanoes

Density

The amount of mass of a substance in a certain unit volume

Freezing Point

The temperature at which a liquid becomes a solid

Ocean Water v.s. Fresh Water Ocean Water Fresh Water

Salinity Average is 35 ppt. (35 g of salt

per L of water)

Varies depending on location

Salinity is greater at the poles and near the equator! WHY?

Density More dense than fresh water

(1.022 kg/L)

Freezing Point -1.90C

Salinity

Very tiny amounts of salt. (~0 ppt.)

Density

Less than ocean water (1.000 kg/L)

Freezing Point

0.0 0C

Dead Sea

Reading Check…pg.17 Questions 1-5

Core Lab Salinity’s Effect on Density – Activity 1-3 A

Sources of Fresh Water Lakes, Ponds and wetlands

Lake and pond is basically a hole in the ground that fills with standing water

Wetland is a low area in the land that is saturated with water all or most of the time and they provide habitat for many plant and animal life

Marshes are an example of a wetland

Streams and Rivers

Fast flowing bodies of water

Streams differ based on the speed, temperature and clarity (turbidity) of the water, as well as the nature of the banks and bottom

Ground Water

Precipitation that falls to the Earth’s surface and sinks out of sight

It sinks into pores in rocks and sinks until it reaches bedrock that it cannot penetrate through

Digging into these pools is how we

create wells

Glaciers

A moving mass of snow and ice.

Found in areas where it is so cold the snow remains all year.

Glaciers in

mountains and on

the continent of

Antarctica

Glaciers slow down the passage of water through the water cycle by storing vast quantities of water. They release the water during the hot summer months.

They give us information about the Earth’s past climates.

Water

trapped in

glacial ice