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Would you like to visit either place?
QOD: Brainstorming… What are the Poles like? What are the similarities and differences between them? Would you like to visit either place?
Comparison of the North and South Poles
1. Both are located at 90 degrees latitude. 2. North Pole lies under the permanent ice pack of the Arctic Ocean 3. South Pole is on the continent (LAND) of Antarctica
The Weather 4. The depth of the ice cap that covers Antarctica is between 9,000-14,000 feet deep. Only a bit of mountainous land peaks protrude through the ice. 5. Wind = average 48 mph all the way to gusts of 150 mph!
6. Both the North and South Poles have SEALS on them.
7. Only the South Pole has penguins. 8. North Pole has polar bears. 9. There are no TREES.
Magnetic North & South Poles
Earth has a magnetic field (imagine a gigantic bar magnet inside the Earth) made of molten iron (molten – liquefied by heat) from Earth's outer core. Two geographic poles (North and South) where spin axis passes through. Also two magnetic poles (North and South) near but not quite in the same places as the geographic poles. The needle in a compass points towards a magnetic pole. When you are far away from a pole, a compass is very helpful if you want to find your way around. The compass needle points due North (or South if you live in the Southern Hemisphere!). However, if you are near either pole, a compass becomes useless. It points towards the magnetic pole, not the true geographic pole. In 2005, the North Magnetic Pole (NMP) was about 503 miles from the Geographic North Pole. The NMP was in the Arctic Ocean north of Canada. The South Magnetic Pole (SMP) was about 1,756 miles from the Geographic South Pole. The SMP was off the coast of Antarctica in the direction of Australia. The magnetic poles actually move around! Remember, swirling motions of molten metal in Earth's outer core make our planet's magnetic field. Those swirling motions are changing all the time. That means the magnetic field is changing, so the magnetic poles move! In the first part of the 20th century, the poles usually moved about 5.6 miles per year. Then, around 1970, they started moving faster. In recent years they have been moving about 25 miles per year! The aurora (Northern & Southern Lights) mostly happen near the magnetic poles. The charged particles (mostly electrons and protons) follow along magnetic field lines towards the magnetic poles. When the particles run into air in the Earth’s atmosphere, the air glows in pretty colors - making the beautiful aurora!
Seasons at the North and South Poles
The North Pole June 21= Summer (sun never sets) Dec 21=Winter (sun never rises) The South Pole June 21= ________ Dec 21= __________ WHY???? Explain.
Key Definitions Glaciers – huge mass of ice over land
Crevasse – a deep crack in a glacier Ice Shelf – an ice sheet attached to land but is projected out over water Ice Cap – dome shaped ice mass over the top of a mountain Icebergs – large mass of floating ice in water Pack Ice – floating sea ice that is driven together over many years by wind & current (i.e. the North Pole)
“Ice berg caught in winter sea-ice”
This ice berg is grounded on the ocean floor (and the other 80-90% of it that you can't see!) and sea-ice has formed around it. The stripes in the ice are formed by snow build up in different temperatures (probably thousands of years ago) when the ice berg was a part of a glacier on continental Antarctica. The small figure is a full-size person.
I've never been anywhere in the world where it is so possible to get as good an impression of the geography of a place as Antarctica. With the land stripped bare of vegetation and virtually nothing in the way of human influences to get in the way, you can just simply see the landscape so much more clearly. From this particular vantage point it is possible to see about 80 miles in all directions to the two peaks 40 miles away and to the ice covered sea an equal distance behind that
Timeline of Antarctic Discovery
: James Cook (English) crossed the Antarctic Circle – never sighted land but was convinced it was there. 1820: Nathaniel Palmer (English) discovered Antarctica. 1880s: Everybody wanted a piece of the new land, but countries must occupy the land to be in control of the territory. Lots of whale hunters Begin to come to Antarctica.
In 1911… Roald Amundsen and Robert Scott (Norwegians) led the first major expedition to the South Pole. R.S. DIED on his adventure, but we have the diary that records their important and detailed findings.
1961: Antarctic Treaty Pledged: To use Antarctica for peaceful purposes and not to endorse any further territorial claims Banned: Military activity Nuclear explosions Disposal of radioactive waste 1991 – mining of fossil fuels
1990 Scientists begin to study the ozone problems from Antarctica.
2006 Scientists say that Antarctica’s ice sheets are melting faster than snow can fall. Researchers determined that between , Antarctica lost its ice at a rate of 36 cubic miles a year. This global warming makes the oceans rise and could over take the low islands in the Pacific and other places around the world.
In 2007, the Intergovernmental Panel on Climate Change (IPCC) released nearly unanimous findings that it is "unequivocal" that the climate is and will continue to change, and that human generation of greenhouse gases is responsible for most related changes since the 1950s.
leARN360 NATIONAL GEOGRAPHIC VIDEO CLIP
leARN360 NATIONAL GEOGRAPHIC VIDEO CLIP
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