Transcript - bYTEBoss

Antarctica
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What are we going to do?
Where is it? What is it? Why it is like
that?
What goes on there? How did that come
about? What are the pressures on it?
What about Antarctica and Global
warming?
What about visiting the place? Would you
like to go?
What have you found out about
Antarctica?
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Mostly you will have come across
Antarctica on a map like this
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How many UKs could fit into
Antarctica?
Guess?
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How can we do it properly?
If we know the area of each location (UK
and Antarctica),
we can divide Antarctica area by the UK
area
Antarctica 13,829,430 km2
UK 224,820 km2
Now calculate about how many countries
the size of the UK would fit into
Antarctica what is it?
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What about the other parts of the world?
Which is it closest to it in size? Which is it just
less than double? Can you put them in order? 6
Upside down world
What is the
nearest continent
to Antarctica?
Approximately
how far is it from
the South Pole to:
The Cape of Good
Hope?
Cape Horn?
In which compass
direction do you
move from
Antarctica to:
South America?
Australia?
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If you have
the
worksheet,
label it
If you do
not have the
worksheet,
you will
need to flick
back and
forward for
this one
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The questions
1. Can you spot three differences between the
ice sheets over West Antarctica and East
Antarctica? Think about their size, the
heights of the ice sheets and the land below
them.
2. If Antarctica’s area is about 14,000,000
square kilometres and the average ice sheet
thickness is 2,450 metres, can you calculate
the approximate volume of the ice in
Antarctica?
3. What do you think would happen to the land
buried under the ice if the ice sheets melted?
Why?
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The next bit is about
what has happened to
Antarctica over time
So just to remind those who have
done it before – and for those who
have never come across it…..
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A thin crust - 10100km thick and
not very dense
The Structure of the
Earth
A mantle – extends
almost halfway to the
centre, hot and dense
A core – made of molten
nickel and iron. Outer
part is liquid and inner
part is solid. Gets hot
due to radioactive decay.
The Earth is believed to be 4500 million years old
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Plates and plate boundaries
The earth's crust is
broken up into pieces.
These pieces are called
plates.
Heat rising and falling
inside the mantle creates
convection currents.
The convection currents move the plates.
The movement of the plates, and the activity
inside the earth, is called plate tectonics.
The point where two plates meet is called a
plate boundary.
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So where did
Antarctica fit into
all this movement?
OR
How Gondwana became the world we
know today
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There is a link
on the wiki to
an animated
version of this
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Let’s see what it is really like!
Antarctica is the
world’s last great
wilderness.
Antarctica is the
world’s last great
wilderness.
It is a continent
almost entirely buried
by snow and ice.
It is so hostile and
remote that it has no
permanent residents.
Surrounded by the
Southern Ocean,
Antarctica covers
nearly 9% of the
Earth’s land.
It is 25% bigger than Europe,
making it the fifth largest
continent.
It is also the least polluted
of all the continents
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Let’s see what it is really like!
Antarctica is divided into
two main areas:
East Antarctica (sometimes
called Greater Antarctica),
and
West Antarctica (Lesser
Antarctica)
They are separated by the
Transantarctic Mountains
that stretch 3,540
kilometres across the
continent.
West Antarctica is the
smallest of the two and has
a peninsula that sticks out
nearly 1,000 towards the
southern tip of South
America
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Let’s see what it is really like!
About 99% of Antarctica is
covered with a vast ice
sheet.
It is the largest single mass
of ice on Earth and is bigger
than the whole of Europe.
At least 3 million years old
(and as much as 30 million
years old in places)
The ice sheet averages
2,450 metres deep and holds
about 70% of the world’s
fresh water.
The average altitude is about
2,300 metres above sea
level.
Vinson Massif is Antarctica’s
highest point, rising to a
height of 4,897 metres.
But in places, the bottom of the
ice can be as much as 3,000m
below sea level.
So they weren’t filled with ice,
large parts of Antarctica would
be under the sea.
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Let’s see what it is really like!
Antarctica’s ice sheet is
constantly on the move.
Huge rivers of ice known as
glaciers are pulled slowly by
gravity from the interior
towards the sea.
Along the way, the ice cracks,
breaks and is ruptured by
underlying rock.
Crevasses up to hundreds of
metres deep can form on the
surface.
On reaching the sea, the
glaciers spill out over the
water’s surface and create
gigantic floating blocks of ice
called ice shelves.
The largest, the Ross Ice
Shelf, is the size of France.
Sometimes pieces of an ice
shelf break off to form
icebergs.
Beyond the ice shelves, much
of the surrounding ocean
freezes over during the
winter.
With this extra winter sea-ice,
Antarctica almost doubles in
size.
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Do they have seasons on Antarctica or
is always just cold?
March
September
Before I get you to count icy squares (1 mill km2
each), I think we need to discuss something – do
you notice anything odd here?
Can you think what is going on?
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