Download File

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 it
It 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 erosion
 How 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 4.4
 Answer 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 Schools
 Earth’s Water: Groundwater reading. Read the
following article. Login to Edmodo to answer
questions associated with the reading.
 4.6 Book Reading with questions
 4.7 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 seamount
 Layers 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.
1
2
3
4
5
6
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 by
1.
2.
Water lying inside a volcanic crater. When this occurs the lakes
are called volcanic lake.
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)
Volcanic Lake
Hoover Dam Lake
Glacier 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 surface
 How 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?
]
 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.