Water, Water Everywhere!Water in Earth’s Processes

UnitS6E3

How is the amount of water on Earth divided up?

3% = Freshwate

r

97% = Saltwater

Is most of the water on Earth freshwater or saltwater?

Saltwater!

Where can the freshwater be found?¾ Freshwater is Frozen Solid in ice caps and glaciers ¼ Freshwater is Liquid underground

A tiny fraction is in lakes & rivers

A smaller fraction is water vapor in the atmosphere

What is the Water Cycle?

Definition: The continuous movement of water from Earth’s surface into the atmosphere and then back again!

The water cycle is powered by the Sun.

Condensation

Precipitation

Evaporation

Accumulation

Trees

Main Parts of the Water Cycle:

Evaporation

Condensation

Precipitation

Accumulation

What is Evaporation?

When water changes from liquid to water vapor (liquid to gas)Evaporation comes from:

• plants• lakes• oceans

Evaporation from plants????

• This is called TRANSPIRATION

What happens after water evaporates?

Condensation!

As air and water vapor rise, they cool to form clouds

(gas to liquid)

What happens when the droplets get too large to stay in the clouds?They fall as Precipitation –water that falls from clouds as

RainSnowSleetHail

What happens to water that falls to the ground?

Accumulation- collection of water

•Runoff – water flows across the land into streams, rivers, or oceans

•Groundwater – water soaks into the ground

Examples of surface water:

•Rivers• Ponds• Lakes•Wetlands – swamps, bogs,

marshes

How does water get UNDERGROUND?

It trickles down betweenparticles of soil & throughcracks in rocks

How water gets into rock…

An Aquifer is an underground layer of rock or sediment that holds water.

How can we get to the water so we can use it everyday?

• Springs can form & water bubbles out naturally

• Wells provide access to Aquifers that have drinking water – Wells can be mechanically or hand

pumped– In Artesian Wells, water rises

because of pressure in an Aquifer

How is water used?• In your home• Industry & Transportation• Agriculture• Recreation

Why is it important to conserve water?

Water Pollution is Bad!

• What is water pollution?• What causes water pollution?

Properties that make up the oceans’ composition:•Salinity• Temperature•Dissolved Gases

Remember…we have more saltwater on Earth than freshwater!

So, why can’t we just drink sea water?

Because it tastes yucky! That’s why!

Why does it taste yucky?Because it has lots of salt…

• Salinity – the amount of salt dissolved in water (NaCl)

• Average salinity of the ocean is 3.5%–If you boiled 1kg of ocean water in a pot until all water was gone, you’d be left with about 35g of salt left in the pot!

Where do the salts and minerals come from?

• Salt and minerals that are in the ocean come mostly from dissolved rocks, and soil that is brought to the oceans from rivers

• Volcanoes also provide salts to the oceans.

What does salt do to the ocean water?

• Lowers the freezing point of water

• It makes seawater more dense

• Greater buoyancy – you float higher in some ocean water

Temperature of Ocean Water

• Closer to the equator = warmer water

• Temperature decrease as you go deeper

• Density & Pressure increase as you go deeper

Dissolved Gases in Ocean Water:

Oxygen Carbon Dioxide

Sea plants & creatures use these gases to survive

Oxygen in sea water comes from Algae& air

One big ocean or several smaller oceans?

• All of the oceans are connected, and essentially one big ocean.

• We have made imaginary boundaries to break up this ocean, and currently we have 5 different oceans.

World’s Oceans

World’s OceansFrom the largest to smallest:

PacificAtlanticIndian

SouthernArctic

Main features of the ocean floor:(F) Continental shelf (C) Abyssal Plain

(A) Continental slope (B) Seamount(E) Volcanic islands (G) Ocean trench

(D) Mid-ocean ridge

What is a wave?

The movement of energy through a body of water

• Surface waves are caused by wind.

• The height and size of waves depend on 3 factors:

Strength of the windLength of time the wind blowsDistance over which the wind blows

Waves