Introduction to Antarctica and the Antarctic, Why is it so cold? Jean Pennycook penguinscience.com

Antarctica or Antarctic? Antarctica is the 5th largest continent on earth and larger than the US and Mexico combined. The word, “Antarctica”, refers to the continent itself. “Antarctic” refers to the entire southern polar region, including the ocean that surrounds this continent.

Most of Antarctica is covered with over 1.25 miles of snow and ice. These large glaciers move toward the coast under their enormous weight and the force of gravity. When a portion floats out over the ocean these extensions are called ice shelves. The Ross Ice Shelf is as large as Texas.

Ross Ice Shelf This is the edge of a glacier that is floating on the water, but is connected to the remainder that is on the land. Picture courtesy of: usap.gov

The ice shelf from the ocean. What you see is only 10% of the height of this mass of ice, 90% is under the water. This is fresh water and was made from snow fall.

The amount of ice in Antarctica plays a very influential role in the Earth’s temperature. Ice reflects most of the sunlight back into the atmosphere without absorbing it. This helps keep the Earth cool.

Map courtesy of Australian Antarctic Data CentreAustralian Antarctic Data Centre This map shows the continent of Antarctica. The glaciers are white and the ice shelves are in gray. Red dots indicate a science research station.

Any place whose latitude is greater than 66.5 o S. In this case here is a map of the Antarctic, defined by what is called the Antarctic Circle. It would include most of the continent of Antarctica and be defined as all places that receive at least one 24 hours of daylight period and one 24 hours of darkness once a year. This boundary would never change as it is defined by latitude.

Because of the angle of the sunlight at the Poles they receive less energy and are therefore much colder than the rest of the Earth. Are the poles equally cold? Average Winter o FAverage Summer o F South Pole North Pole-1535

1 Antarctica- Climate -The ‘frozen Continent’- 90 % of the world’s ice is in Antarctica -Almost all land is covered in ice sheets - Very short cold summer -Very long cold winter -Windiest place- severe winds -Driest place with less than 4cm of rainfall -Only one period of daylight that lasts for 6 months -90% of the sun’s reflection bounces off the ice- so only 5-10% is available for warming

1 The effects of Global warming on Antarctica -Ice caps melting causing rising sea levels, flooding some coastal cities. -The decline of penguins who rely on ice for their nesting habitats -Ice shelves break up

Challenges to Life at the Poles Plants and Animals must adapt to: –Cold –Drought –Short growing season –Long days, Long nights More recently, small changes in climate can mean dramatic changes for life at the poles

Tundra Plant Facts –Grow in clumps –May bloom from buds that are one to two years old –Seeds may germinate and grow while still attached to parent plant