The words “polar” and “desert” may seem contradictory, but that’s only because most of us associate the latter with sun-drenched, sand-covered landscapes. Yet desert actually describes any desolate stretch of land that is waterless and without vegetation—and by that definition, Africa’s Sahara doesn’t hold a dowsing rod to the Antarctic desert and the polar deserts of the Arctic.
In sheer land mass alone, Antarctica’s polar deserts scorch the competition—covering more than 5.5 million square miles, they comprise an area larger than the Sahara, Arabian, Gobi, and Kalahari combined. (The Arctic comes in a close second at 5.4 million.) While a desert landscape is defined as an arid region that receives less than 10 inches of precipitation a year, Antarctica gets only about two inches annually. Its aptly named Dry Valleys haven’t seen rain for at least 2 million years!
Made up primarily of bedrock, large boulders, and gravel plains, Antarctica’s Dry Valleys are dotted by a number of frozen, hyper-saline lakes including Don Juan Pond, the world’s largest. (With a saline level over 40 percent, it is also the saltiest body of water on Earth, beating the Dead Sea by nearly 10 percent.) That’s not exactly the picture you think of when you hear “White Continent,” yet the effect is caused by the snow-covered Transantarctic Mountains. This mile-high range, which divides the continent, serves as a natural barrier for the East Antarctic Ice Sheet. Given the valleys’ arid environment, any ice that does break off the surrounding glaciers immediately turns into vapor, totally bypassing the liquid stage.
The average winter temperature in Antarctica’s polar deserts is around -20 degrees Fahrenheit, and can drop as low as -90; during summer months, it can warm up to a balmy 30 degrees, producing short-lived streams that link the lakes. Also during warmer months, there is nearly 24 hours of daylight, while the reverse is true during the cold season.
While explorers long believed that these Dry Valleys could not sustain life (Robert Scott, who discovered the region in 1903, called it “a valley of death”), scientists in the 1970s unearthed a number of microorganisms in the area. Since then, nearly 350 vascular species have been found, and it is estimated that nearly 5 percent of Antarctica’s polar deserts are covered in some flora, although the tallest shrubs reach no more than three feet in height.
To learn more about our upcoming expedition to the region, check out our Antarctica, South Georgia & the Falkland Islands cruise.