ENVIRONMENT

Using new satellite data from Antarctica’s eastern highlands, scientists have measured the most frigid temperature ever recorded: about -93°Celsius (-136°Fahrenheit). (National Geographic News)

Use our resources to learn about Earth’s extremes, from highest and lowest, to hottest and (new) coldest!

Discussion Ideas

• The coldest temperatures in the world have been consistently recorded in the interior of Antarctica, although the Arctic is also pretty chilly. Why do you think Antarctica is so much colder than the Arctic?
  • Antarctica is consistently colder than the Arctic for three main reasons.
    • Antarctica is a continent, while the Arctic is mostly covered by the ocean. The ocean absorbs more sunlight and stores more heat than land. The ice covering the Arctic is “warmed” by the ocean, and reaches higher temperatures than the Antarctic ice sheet.
    • The surface elevation of Antarctica is about 5,000 meters (16,404 feet) higher than the Arctic, which rests at sea level. Higher elevations usually result in colder temperatures.
    • (This is the tricky one!) The Earth’s orbit around the sun is not a perfect circle. It’s a slight ellipse. When the Earth is closest to the sun, it is at perihelion. When the Earth is farthest away from the sun, it is at aphelion. Aphelion occurs during the Antarctic winter—in 2014, it will be around July 4. (In contrast, perihelion occurs during the Arctic winter—in 2014, it will be around January 4.) So, Antarctica receives even less solar radiation during the winter, making it even colder. Aphelion has a much less powerful impact on Antarctica’s climate than its position as a continent with high surface elevation, however.

• In the video accompanying the Nat Geo News article, the scientist says that measuring the temperature in Antarctica’s coldest regions requires sophisticated technology. Traditional mercury or alcohol thermometers won’t work. Why not?
  • It’s too cold!
    • Mercury freezes (becomes a solid) at about -39°Celsius (-38°Fahrenheit). It’s useless for measuring temperatures below that—and the new coldest temperature is almost two-and-half times that cold!
    • Alcohol thermometers, which use ethanol (not mercury) as their liquid, can be used to efficiently measure temperatures to about -70°Celsius (-94°Fahrenheit). That is still too warm for Antarctica’s cold mountain slopes.

• Antarctica’s new low broke a 30-year record for the lowest recorded temperature on Earth. Read through our “Earth’s Extremes” GeoStory, which lists the hottest, coldest, highest, lowest, and most isolated places on the planet. What other “extremes” do you think might be updated? Which ones do you think are unlikely to change?
  • Likely to be updated: Although climate is fairly predictable, new temperature or precipitation records may be set in the near future. Volcanic eruptions may create new islands in the ocean. Explorers are discovering new cave systems all the time—one of these may turn out to be the world’s largest. Scientists may also discover and date a material that is even older than the Jack Hills zircons, the oldest material on Earth.
  • Unlikely to be updated: The world’s highest and lowest elevations, and measurements of the world’s rivers and lakes are probably very stable and unlikely to change. Areas “furthest from another piece of land” and “furthest from the ocean” are also unlikely to change.

Related articles

• Coldest Places on Earth Found, In Antarctica, Of Course (livescience.com)
• Landsat 8 helps unveil the coldest place on Earth (sciencedaily.com)