Geography Awareness Week, also known as GeoWeek, is celebrated every year during the third week of November. The goal of the week is to get people excited about geography and help them learn more about the world around them. Every year, we present fun facts to help you get excited about Geography Awareness Week. This year our subject is very dry subject- deserts.
Imagine a desert. What do you see?
Most people probably envision a hot and barren landscape. Perhaps it is covered by flowing sand dunes. Covering over a quarter of the world’s land surface, deserts come in many shapes and sizes. Here are ten fun facts designed to clear up some misconceptions about these dry landscapes and highlight some of the world’s more extraordinary deserts.
1.) Not All Deserts are Hot
Not all deserts are hot, but they are all dry. An area’s status as a desert is determined not by its temperature, but by the amount of precipitation it receives. A desert is an area that receives on average less then 250 mm (10 in) of precipitation per year. Because precipitation, not temperature, determines if an area is a desert, they can be found all across the globe from the equator to the poles and everywhere in between.
2.) Not All Deserts are Sandy
The classic image of desert has rolling sand dunes. Most deserts, however, do not actually have much sand. It has been estimated that only about twenty percent of the world’s deserts are sandy. Lacking much rain, wind is the primary driver in shaping a desert’s landscape. In the majority of deserts, wind blows small particles, like sand, away leaving a landscape of large rocks or hard-packed soil.
3.) Largest Desert
With an area of 5,400,000 square miles, the world’s largest desert is the continent of Antarctica. It might not seem like it, because it is covered with snow and ice, but Antarctica is actually one of the driest places on Earth. Not even on the coasts, its wettest areas, does Antarctica receive more than 200 mm of precipitation per year.
4.) Largest Non-polar Desert
Though smaller than the Antarctic and Arctic Deserts, the Sahara is still an immense desert. Covering over 3,500,000 square miles, the Sahara stretches across North Africa from the Red Sea to the Atlantic Ocean. Parts of ten countries (Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan, Tunisia) make up the Sahara Desert.
5.) Driest and Highest Altitude Desert
The Atacama Desert, located along Chile’s Pacific coast, does double duty as the driest and highest altitude non-polar desert. With an average of less than 15 mm of precipitation, the Atacama Desert is, with the exception of parts of Antarctica, the driest place on Earth. The Atacama also stretches into the Andes Mountains. Mountains as high as 20,000 feet in the Atacama Desert do not have snowcaps.
6.) Largest Contiguous Sand Desert
Most of the world’s deserts are not sandy, but if there is a desert that most closely resembles the stereotypical image of a desert, it would be the Rub’ al Khali. A part of the Arabian Desert, the Rub al’ Khali has an area of 250,000 square miles and is covered by red sand dunes that can reach over 800 feet tall. Rub al’ Khali, meaning the Empty Quarter in Arabic, earned its name because its harsh landscape has kept it largely uninhabited.
7.) Smallest Desert
Located in the Canadian Yukon territory, the Carcross Desert is often labeled as the world’s smallest desert. Covering only a single square mile, Carcross is definitely small. The problem with Carcross, however, is that it is not actually a desert. No one would call Carcross, with an annual average of 20 in of rain, a wet place, but it does receive too much precipitation to be a real desert.
8.) Most Extreme Temperatures
From blazing hot to dangerously cold, deserts can be any temperature. The records for the highest and lowest temperatures were both set in deserts.
The world’s hottest recorded temperature, 134 °F, was set in the United States’ Mojave Desert’s Death Valley. The record for the coldest temperature, −128.6 °F, was set at Vostok Station in Antarctica.
9.) Not All of the Continents Contain Their Own Desert
Every continent, except for one, contains at least one desert within its borders. Unlike the other continents, Europe does not have its own desert. Europe does have dry and sometimes sandy areas, but none that receive less then 250 mm of precipitation. The Arctic Desert does include parts of Europe’s more northern countries, such as Sweden, Norway, and Finland, but it also includes parts of Asia and North America.
10.) Deserts Change Over Time
The Atacama Desert may have been dry since the Triassic Period 200 million years ago, but most deserts change over time. Now located in the American Great Plains, the Sandhills in Nebraska was once part of a desert that disappeared around 800 years ago. The Sahara Desert, on the other hand, used to be a wet and fertile place five thousand years ago. Ancient rock art found in the Sahara depicts a range of animals, such as giraffes and hippopotamuses, that you would not find in the current desert. The Sahara is also still growing. In part due to a warming climate, the Sahara desert has increased in size by around 10 percent in the past hundred years.
Bonus Fact: Deserts are not Just Found on Earth
The planet Mars has a large sandy desert. Because of its red dunes and sandstone cliffs, the valley of Wadi Rum in the Arabian Desert is frequently used as a stand in for Mars in many films. Wadi Rum has also been the location of fictional deserts such as the moon of Jedha in Rogue One: A Star Wars Story.