Download
1 / 21
210 likes | 454 Vues
Antarctica. 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?
E N D
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?
Mostly you will have come across Antarctica on a map like this
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?
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?
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?
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
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?
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…..
A thin crust - 10-100km thick and not very dense 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 Structure of the Earth The Earth is believed to be 4500 million years old
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.
So where did Antarctica fit into all this movement? OR How Gondwana became the world we know today
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 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 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. 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. Let’s see what it is really like!
Do they have seasons on Antarctica or is always just cold? • 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? March September
