Water Systems

Sections 4.1 -4.10

It is in the food you eat and the air you breathe

You bring it into your home, use and dispose of it every day

Most of your body is made of itIt shapes our weather and world

Water 4.1

Water is vital We need it to live

Is it easy to get the water we need?

70% of the Earth is covered in water. That is why we call it the blue planet, as it appears blue from space

Why do we need to protect our water if there is so much of it?

About 3% is fresh water. Most fresh water is frozen Only 1% of the water in the world is useable liquid

Why is water considered a special element ? It can exist in 3 different states, which most cannot Solid Liquid Gas

Read through chapter 4.1 page 209

Answer questions 1, 2, 4, 6.Define Salinity, Estuary, Fresh Water,

Meltwater

4.3 The Water Cycle

If pure liquid water is scarce, how do we continue to get it?

The water cycle is responsible for much of our weather; It keeps rivers and lakes full, and that allows water to purify itself and sustain many forms

The sun causes water on Earth’s surface to change to water vapour in a process called evaporation

Where does water go that humans, animals and plants consume?

Humans perspire (sweat) and plants transpire. The evaporation of water from plants is called transpiration.

Condensation is the process of water vapour changing back into liquid .

These droplets form with dust/dirt particles to form a cloud.

How does the sky release the water?

So much water gathers in the cloud that it becomes too heavy for air to carry it; precipitation happens

What are some kinds of precipitation? Rain, hail, snow and sleet

Snow can land on mountains and remain frozen for hundreds of years. If it continues to accumulate the pressure will eventually turn that ice into a glacier. Sublimation can occur from ice. It is the process of turning ice directly into water vapour.

Is precipitation pure water?

No, once it evaporates it leaves the salt and pollutants behind. But it can recollect chemicals and pollutants as it returns to liquid form, so it is not necessarily pure/ or as clean as before.

1. NAME AND DEFINE THE 4 CHANGES OF STATE THAT OCCUR WITHIN A WATER CYCLE

2. ILLUSTRATE A PICTURE THAT OUTLINES THE WATER CYCLE. MAKE SURE TO LABEL THE CHANGES OF STATES. BE DETAILED AND BE CREATIVE.

4.4 The Power of Water

How is water destructive?

Have you ever noticed rivers looking red or muddy? After a heavy rain erosion can occur. Erosion – the

carrying away of sediments by water Sediments – are soil particles that are moved from

one place to another by erosionHow is erosion destructive or dangerous?

Organisms in water have less light to make food ( plants) and have less oxygen

Erosion: How stuff works?

Erosion at its finest

Where does the sediment go? It eventually settles on the land but not after it cuts

and scrapes the land causing rills Rills – grooves formed from travelling sediment Sometimes the sediment only collects at the mouth of

the river – these are called Dredges These slow down water and can possibly form Floods Floods occur when the water has no where to go.

They occur when rivers cannot hold the heavy runoff They occur when riverbanks have been clear cut They occur when the spring thaw occurs rapidly

Can you think of another destruction of water? Avalanches! These are caused by temperature change and sudden

vibrations

Read through Case Study 4.4Answer questions 1, 2, 4

4.5 The Water Table

Much of the Earth's potable water is actually locked up underground, and while it may not be as physically obvious as big lakes and rivers, it is critically important.

Potable water is water suitable for consumption.

When underground water deposits are large enough to be considered sustainable for use, they are known as aquifers.

Water ends up underground because of its attraction to soil particles. A water molecule acts like a magnet attracting itself to other water molecules and to soil particles molecules.

Ground Water

Precipitation sinks into the ground by gravity and by the attraction of the water to soil particles.

Water sinks deeper and moves into all spaces between the soil particles. This is called percolation. This water is now considered to be ground water.

The very bottom layer of earth(called the aquitard) is impermeable to water so the water remains above it in a layer called the saturated zone.

This saturated zone would be an aquifer. It is an excellent source of useable water.

The Water Table

The water table is a term used for the upper limit of the saturated zone. It rises and falls as water from the saturated zone depletes.

With heavy precipitation, the water table level moves into the unsaturated zone or zone of aeration

In times of drought, when water is scarce, water from the saturated zone is then drawn up through the soil because of the attraction of water molecules to soil particles. This process is called capillary action.

Homework Assignment: Do questions #2 and 4 page 217 Reading :Water Science for SchoolsEarth’s Water: Groundwater reading. Read

the following article. Login to Edmodo to answer questions associated with the reading.

4.6 Book Reading with questions4.7 Book Reading with questions

4.8 Floods: Water Untamed

Flood – a place is in flood when excess water flows over a river into its flat areas next to it

Flood plains – the flat area on the sides of the river which regularly gets submerged in water

Floodway- a concrete river channel designed to carry floodwaters safely away from homes and buildings

Floodways are built when communities have reoccurring flooding problems

Read through pages 222-223. Do career profile on Hazel Breton

4.9 Geological Features at Sea and on Land

Plate Tectonics?

Plate Tectonics describes of the moving of the Earth’s crust.

The plates move over hot mantle beneath them causing them to crash into each other. This formation shapes both the land and the floor of the ocean.

Features

The Continental Shelf

The extension of the Earth that slopes gently into the ocean is called the continental shelf.

The continental shelf is very active with sea life

The larger drop off from the shelf to the ocean floor is called the continental slope.

How do mountains form?

The biggest and longest mountain ranges are under water. The largest is the Mid Ocean range and is between N.A and Europe. It is over 60 000 km long.

Volcanoes – are mountains formed when hot lava erupts through the Earth’s crust. It cools and solidifies to rock.

An underwater volcano is called a seamountLayers of rock will eventually build up on that

seamount. It will rise above the ocean forming a Volcanic Island ( like Hawaii)

Guyots were volcanic islands who’s tops have eroded off, and are now under water again.

Trenches are steep drops in the ocean’s floor that form when one of the Earth’s plates slides under another.

An example of a famous trench is the Mariana Trench of the Pacific Ocean. The Mariana’s Trench is home to the deepest surveyed part of the ocean; The Challenger Deep . It is over 11 km deep.

Scientists need special submarines to explore the strange creatures there.

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Canyons

Canyons – are deep steep sided valleys

They are formed when fast flowing rivers cut their way through rock

They can exist both on land an in the sea.

Lakes – are bodies of water that lay within a low spot on the earth (also known as a basin) .

Basins and their lakes areformed by1. Water lying inside a volcanic crater. When this occurs

the lakes are called volcanic lake.2. Water that has melted from a glacier.

Glacier carves Basin – Ice Melts – Lake forms

This is how most of the lakes in Canada formed including the Great Lakes.

3. Water that has been blocked. It can be either caused by us or by nature. ( A man made dam or one by pesky beavers)

Hoover Dam Lake

Glacier LakeVolcanic Lake

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river.

They flow downhill pulled by gravity

Rivers

Tributaries – are small streams or rivers that join a parent river.

All rivers carry sediment; how much depends on the speed of the water flow.

Rivers – there are lots of different types of rivers......

Braided River and Meandering River are two types.

Watersheds

Watersheds – the area where all water drain into that is surrounded by high land

(Sometimes called drainage basins)Canada has 4 major watersheds

In Canada, all watersheds will eventually flow into one of the three oceans.

• The Atlantic• The Pacific• The Arctic ( includes the Hudson’s Bay)

Where the water flows?

The continental divide separates waters flowing into the Pacific from those going to the Arctic and the Atlantic

Answer questions 1, 2 and 6 page 227. To be handed in for evaluation.

4.10 Glaciers

Glaciers - masses of snow and ice that have built up over thousands of years.

4.10 Glaciers: Rivers of Ice

Glaciers cover 3% of the Earth’s surfaceHow glaciers form:

The mass of new snow changes lower layers into ice, and when this becomes thick and heavy, it begins to move.

Two types of glacier movement: Plastic Flow - occurs within the ice of a glacier. Occurs when

the glacier is 50 m or more in depth. The pressure from the above layers is too much for the snow/ice beneath causing the top layer to move faster.

Basal slip – occurs when the entire mass of ice slips over the ground because of a layer of melted water between it and the ground. As the pressure increases toward the base of the glacier, the melting point of water decreases, and the ice melts.

Rocks and dirt (drift) are pushed ahead of the advancing glacier, leaving mounds of dirt called moraines when the glacier retreats.

Types of Glaciers

An alpine glacier ( or called a valley or mountain glacier) is a long, narrow glacier between the steep sides of a mountain valley, usually following a channel worn by running water.

Can range in size from a patch of ice to several thousands of square kilometres.

Found in all latitudes including the tropics

A continental glacier forms when snow and ice accumulate on polar land. These are the largest types of glaciers.

For example Greenland.

Alpine glacier

Continental glacier

Piedmont (a gentle slope leading from the base of mountains to a region of flat land.) formed from the merger of several alpine glaciers.

Exists in lower slopes of mountains; several thousand to tens of thousands square kilometers in area.

Places such as lower slopes of the Himalayas & Andes

Alpine glacier

Piedmont glacier

When a glacier melts, it deposits a debris called till, that it captured during its trip. Till contributes to the formation of the moraines.

When a glacier meets a lake or ocean, huge blocks of ice break off. These are icebergs.

The continental glaciers of Antarctica and Greenland are the major sources of icebergs. Does this mean icebergs are fresh or salt water?

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Polar Easterlies – are strong winds formed from the cool air surrounding continental glaciers

Polar Ice Cap – a large sheet of ice from the Arctic ocean that causes similar weather effects as continental glaciers

Ice Age – a time 2 million years ago when North America and many other continents were covered by ice.