Transcript What is a glacier?

Insert picture of glacier
DO NOW ACTIVITY: Describe this picture in one word
Beth Harries, Central Foundation Boys’
School, London
Glaciation
Lesson Objective
To be able to identify a glacier and explain how it shapes the landscape
To discuss ideas in groups
Outcome of our learning...
By the end of the lesson
ALL will be able to identify what a glacier is and work collaboratively
SOME will move on to explain how it shapes the landscape and develop
leadership skills
Beth Harries, Central Foundation Boys’
School, London
Open your envelopes.
Put the story in order from when Joe
wakes up.
Beth Harries, Central Foundation Boys’
School, London
Joe woke up and opened the curtains and for the second day in a row saw
nothing but a blanket of snow. His mobile frantically beeped and before he
knew it, Joe was at Shoreditch Park building a snowman.
They began to build and the snow was really easy to pack, maybe because it
had fallen on yesterday’s layer.
As they rolled the snow, the tiny snowball quickly began to grow gaining mass.
It morphed from something white and beautiful to an off-white, speckled
mess. Joe pointed out that half of the park seemed to have become
embedded in the snowman.
They looked at what was stuck to the body of the snowman. It had taken a fair
chunk of the path with it. There was mud, lots of odd stones randomly
scattered, leaf debris and pieces of wood.
They finished and looked at the park. The course of destruction couldn't be
disguised. A line of green was left . The ball of snow had the power to strip out
nearly everything in it's path.
Beth Harries, Central Foundation Boys’
School, London
Lesson Objective
To be able to identify a glacier and understand how it shapes the landscape
To develop skills of collaboration
Part 1
In pairs you have 10 minutes to research your area of
glaciation.
Take notes in the correct box and be prepared to teach the
class about your area.
Consider key words, locations, facts and
figures, and collaborate well.
Beth Harries, Central Foundation Boys’
School, London
You may want to
explain in more
detail...use the back
of your sheet
Britain in the ice age
Once upon a glacier...
Many landscapes were once shaped by ice.
In the past the climate has been much colder. These ice
ages were times of glacial activity.
Insert UK map
Insert picture
of u shape
valley
The last ice age started 100,000 years ago and ended
10,000 years ago.
During theses times Scotland and northern England were
covered in ice (see the map).
Glaciers carved new features into the landscape with great
erosive power.
Where’s the ice today?
You can see the evidence
of glaciers today...a ‘u’
shaped valley once
formed by a glacier in the
Lake District and a scar
form meltwater in North
Yorkshire.
Antarctica. 90% of Earth’s ice is found here.
The ice is sometimes over 4000-5000 metres
deep. This ice sheet would cause the earth’s
oceans to rise by 7 metres if it melted.
There are glaciers all over the world in
cold climates. Some are growing, but
most are retreating.
Beth Harries, Central Foundation Boys’
School, London
Britain covered by ice - glaciers
Britain not covered by ice
Think quick!
Why are most of
the world’s
glaciers
retreating?
A glacier is a large mass of ice on land that moves
downward. It is a system of inputs, stores, transfers,
and outputs, just like a river.
What is a glacier?
Inputs come from avalanches along
the sides of the glacier but mainly
from precipitation as snow.
Compacted ice at Puerto
Moreno Glacier, Argentina.
Over time snow accumulates and
is compressed into ice. The water
held in storage is the glacier.
Precipitation
as snow
Under the force of gravity, the
glacier flows downhill.
Insert accumulation and
ablation image
When temperatures warm, glaciers
melt. The melt water is the main
output, along with some
evaporation. This is ablation.
Winter
Summer
_more precipitation (input)
than melting (output) at the head
_more melting (output) than
precipitation (input)
_this is called accumulation
_this is called ablation
Result = advancement or glacier
growth
Result = retreating or shrinking
glaciers
Think quick!
Why are most of
the world’s
glaciers
retreating?
Beth Harries, Central Foundation Boys’
School, London
How do glaciers work?
A glacier is a large mass of ice on land
that moves downhill due to gravity.
1. Freeze Thaw Action
They move slowly, 3-300metres a year.
_Water is trapped in the rocks
_It expands as it freezes
_Places pressure on the rocks
_This is repeated and rocks loosen
and break off
Insert freeze thaw and
plucking picture
As glaciers move, they carry out processes of
weathering and erosion. They have great power
and carve new features into the landscape.
2. Plucking
_Water freezes on the
rock surface.
_The glacier moves downward
_It pulls away rocks from the
surface, plucking away.
3. Abrasion
_Rock fragments in the ice grind against
the surface rock.
_It acts as a rough sandpaper
wearing away the valley.
Think quick!
Why are most of
the world’s
glaciers
retreating?
Insert picture of
glacier
Glacial movement in Alaska
Beth Harries, Central Foundation Boys’
School, London
Lesson Objective
To be able to identify a glacier and understand how it shapes the landscape
To develop skills of collaboration
Part 2
Learn from your peers about glaciers.
Listen well and take notes to complete your grid as they
teach you.
You may want to
explain in more
detail...use the back
of your sheet
Beth Harries, Central Foundation Boys’
School, London
Joe woke up and opened the curtains and for the second day in a row saw
nothing but a blanket of snow. His mobile frantically beeped and before he knew
it, Joe was at Shoreditch Park building a snowman.
They began to build and the snow was really easy to pack, maybe because it had
fallen on yesterday’s layer.
As they rolled the snow, the tiny snowball quickly began to grow gaining mass.
It morphed from something white and beautiful to an off-white, speckled mess.
Joe pointed out that half of the park seemed to have become embedded in the
snowman.
They looked at what was stuck to the
body of the snowman. It had taken a
fair chunk of the path with it. There was
mud, lots of odd stones randomly
scattered, leaf debris and pieces of
wood.
They finished and looked at the park.
The course of destruction couldn't be
disguised. A line of green was left . The
ball of snow had the power to strip out
nearly everything in it's path.
Remember Joe?
On the back of your sheet
explain how his story links
to the lesson.
‘Building a snowman is like
a glacier because...’
Beth Harries, Central Foundation Boys’
School, London