Polar deserts are peculiar places. They’re covered in ice sheets, essentially frozen water, so they’re very different from their sizzling, sandy cousins. But with less than 250 mm of rain a year, they’re also incredibly dry. There are two places on Earth where we can find polar deserts: the Arctic and the Antarctic. But very few realise how vital these seemingly lifeless landscapes really are to, well, the entire world. How many of these fascinating facts about polar deserts are news to you?
1. Life underneath the ice
Polar deserts may seem like they are devoid of any life, but don’t be fooled by the ‘barren’ icy landscape. Sure, you won’t see any trees or animals, except from some incidental moss and a very rare polar fox in the Arctic. But right below the ice caps, you’ll find one of the richest microbial ecosystems on Earth. You’ll need microscopic vision to see over half of the creatures in the Arctic and Antarctic. Still, besides the plankton, algae and krill, there are also populations of squid, octopuses, seals, fish, and whales that thrive underneath the ice. Even groups of king penguins can survive in certain parts of the polar desert in Antarctica by looking for food below the surface.
2. Ancient fossils, hidden in the desert valleys
In the Antarctic polar deserts, there are certain ‘dry’ valleys in-between the mountains. Surprisingly, these valleys receive almost no rain or snowfall whatsoever. Especially from above, it’s a curious sight: right in the middle of a seemingly endless sea of ice, there are rocky valleys of naked stone. Paleontologists sometimes call these valleys ‘fossil oases’, because they are the perfect environments to look for traces of ancient life. These areas are almost never visited by humans, so nobody can damage or destroy the ancient traces. But most importantly; the lack of ice exposes layers of prehistoric soil that we normally never see.
3. Even dryer than the Sahara desert
It’s one of the most unlikely facts about polar deserts: some inland areas of the Antarctic polar desert can be so incredibly dry, that even the Sahara desert experiences more precipitation in one year. The most extreme regions in Antarctica only receive about 60 mm annual rain or snowfall. Since the low temperatures prevent any evaporation, the ice sheets remain. This means today’s ice sheets are a build-up of thousands of years of occasional rain and snow.
4. 90% of all of the ice on Earth
The Antarctic polar deserts, as well as its surrounding areas, are home to about 90% of all the ice on planet Earth. About 97% of the surface of Antarctica itself consists of ice, although climate change is causing temperatures to rise. Although most of us may not be very aware of their existence, the polar deserts form a vital ecosystem that protects the global balance in climate zones. If all of the ice in Antarctica would melt, it would cause the oceans to rise up to 60 metres.
5. The largest deserts on Earth?
If we stick to the less than 250 mm of rainfall rule, the polar deserts are actually the two largest deserts on Earth. It hasn’t been this way for millions of years, however: much of the polar deserts were formed during the recent ice ages, so they are really quite young. The Antarctic Polar Desert is the largest of all, followed by the Arctic Polar Desert. The largest non-polar desert is the Sahara.
Curious to discover more fascinating facts about the most unusual places on the planet? Then you might want to have a look at the other articles we have published so far.