Week 3
17 July 2006

Antarctic Extremes

These days, the word extreme is used to market everything from sports adventures to power drinks. Antarctica, however, has weather conditions that truly merit  the word extreme.

Extreme Cold:

The lowest temperatures in the interior are from -40C to -70C during the winter.  In the summer, those temperatures rise to temperatures between  -15C to-35C. The coasts are warmer, with temperatures in the winter ranging from -32 C to -15C and from -5C to 5C during the summer. The coldest months are June and July, the warmest December and January.

What are the temperature ranges in the area where you live? Which month is the coldest and which is the warmest? After you find the temperatures in Fahrenheit, convert them to Centigrade.

Extreme Ice

Antarctic World Records: At the South Pole the temperature can drop to -60C. The lowest temperature ever recorded in Antarctica was -89.2C in July 1983 at Vostok Station. Vostok station is at an altitude of 3500 meters. (The warmest temperature ever recorded in Antarctica was 15 C )

Why so cold? One reason is the drift of Antarctic into the southern polar region. (Remember Gondwana before she broke up?- See Week 1) Another reason was the creation of Drake Passage. This gap between the continents of South America and Antarctica allows an unencumbered flow of the Antarctica circumpolar current, keeping the waters from mixing with warmer Atlantic and Pacific currents.

What geographical features affect the temperature where you live?

Extreme Winds: The Antarctic blizzards are the strongest winds on the planet. Wind speeds of up to 320 km/h have been recorded. The highest winds are usually in the coastal regions. Katabatic winds are created when denser colder air is swept off the polar plateau by its own weight. At Cape Denison, wind speeds reach hurricane levels every 3 days.

Look up the strength of the strongest winds in your area.

Extreme Drake Passage	Extreme(ly) Beautiful Sunset - (my photo)

Extreme Dryness: Antarctica is the most arid continent. The snowfall level is usually less than 10 cm annually, although areas of the coast and the peninsula may reach 30 cm.

What is the annual rainfall in your area?

Extreme Altitude: The mean elevation of Antarctica is 2250 m, making it the highest continent.

Where is the point of highest elevation in your state? How high is it?