Our planet is home to a large variety of landscapes, all with different climates and habitats. From the highest peak to the deepest ocean and the cold of the Tundra to the heat of Death Valley, this Earth is a place of extremes. Deserts are one of those places, areas that are generally very dry with unforgiving climates and temperatures wild enough to make them almost uninhabitable. Most of the great deserts in the world are located in the polar regions, since deserts are defined by the amount of precipitation they get, not sand and heat, as many people tend to think. However, deserts are located all around the world (with many in Africa and Australia), though they aren’t all of the same caliber. Here are 9 of the most extreme deserts around the world.
We typically think of deserts as hot, dry places like the Sahara. In fact, when someone says “desert,” we often think of sand and sun. But deserts, in the most scientific sense, are actually classified by the amount of precipitation they receive. That means that cold polar places, which receive relatively little snowfall, are actually deserts too. Using this criteria, Antarctica is the largest cold desert in the world, averaging just 166 mm (6.5 inches) of precipitation each year. The continent spans 14 million km (5.4 million miles), making this desert the largest in the world. Although we’d typically think of Antarctica as a “wet” place, thanks to an abundance of snow and ice, the simple fact of the matter is that the temperatures on the continent are so cold and the air is so dry that precipitation including snow and rain just doesn’t happen.
If someone says desert, you likely think of miles of sweltering sun on rolling sand dunes, winds gusting across them. Welcome to the Sahara Desert, the world’s largest hot desert – and the prototype for all other “deserts.” The Sahara is such a textbook desert that its very name is the Arabic word for desert and is also known as “The Great Desert.” Spanning nearly 9.5 million km (3.6 million miles) in Northern Africa, it’s the third-largest desert, after the Arctic and Antarctic. While the Sahara does have ergs (or sand seas) and dunes can be over 180 m (590 ft) tall, most of the geography is hamada, or rocky plains. This desert is comprised of several “subdeserts,” such as the Libyan desert, which rivals the Atacama as the world’s driest place.
Great Basin Desert
The boundaries of the Great Basin Desert are actually somewhat fuzzy, but most people agree on one thing: it’s the largest desert in North America, even if we aren’t entirely sure just how big it is. Like the deserts of South America, the Great Basin Desert was created by the rain shadow of the Rocky Mountains. Encompassing most of Nevada and stretching into California, Idaho, and Utah, this desert is known for extreme temperatures with daytime temperatures exceeding 32°C (90°F) and dropping as low as 4°C (40°F) overnight. Summers are hot and dry, while winters are cold and snowy thanks to frigid alpine ridges. Although temperatures can be more extreme in the nearby Mojave and Sonoran deserts, the Great Basin Desert owes its more “moderate” climate to its elevation: there are up to 33 peaks that exceed 3,000 m (9,800 ft)!
Much like how the Sahara is the name on everyone’s lips when they talk about deserts, the Arabian Desert is what everyone pictures. This tract of 2 million+ km (900,000 miles) stretches through Yemen to the Persian Gulf and Oman, to Jordan and Iraq. This vast swath of dry wilderness is home to isolated sand seas; the center of the desert is the Rub’al-Khali, one of the largest continuous bodies of sand in the world. Since the area is so large, it is possible to subdivide it into different regions and some areas receive 100 mm of rain per year, while others receive as little as 50 mm. Daytime temperatures soar and drop at night, sometimes to the point of freezing with record highs exceeding 50°C (122°F). The Arabian Desert receives around 3,400 hours of sunshine per year, making it one of the sunniest places on earth.
South America has a reputation for tropical rainforests, but the topography of the continent is actually highly varied, from the wetlands of the Amazon to the peaks of the Andes to the arid region of the Atacama. But the Atacama isn’t the only desert in South America – not by a long stretch. The Patagonian Desert, near the southern tip of the continent, is actually the largest South American desert and the seventh-largest in the world. Located primarily in Argentina, with small portions in Chile, the Patagonian Desert accounts for 673,000 kilometres (260,000 miles) of the region’s surface. Like the Atacama, this desert lies in the rainshadow of the Andes. The weather, however, is colder: the temperature averages just 3 degrees Celsius and rarely exceeds 12 degrees Celsius . Winter lasts for 7 months of the year and even in summer, frost is common.
The Gobi Desert stretches for over 1 million kilometers (500,000 miles) across northwestern China and southern Mongolia. The desert is a rain shadow formation; the high peaks of the Himalayas block rain-carrying clouds from the Indian Ocean from reaching the Gobi, resulting in an area that receives annual rainfall of less than 8 inches. Much of the precipitation the desert does receive occurs in winter, as wicked winds blow in moisture from the Siberian steppes. While there are some sand dunes, much of the Gobi is simply barren or exposed rock. The climate is extreme, with frigid winters and hot summers; temperatures can fluctuate as much as 35°C in the span of 24 hours. But most alarming is that the Gobi has been expanding at a rate of about 3,600 km (1,390 miles) per year and dust storms have been increasing in frequency over the last 20 years.
Great Victoria Desert
Mention of Australia tends to evoke images of the Outback, a desert area with little life and harsh climates. While much of the continent is covered by arid areas, it’s not just one big desert. The Great Victoria Desert, located in south and western Australia, is the largest of all Australian deserts, covering approximately 350,000 km (135,000 miles). The average annual rainfall is irregular, ranging between 200 and 250 mm (8 and 10 inches). The temperature is also variable with daily highs reaching 40°C (104°F) in the summer, and lows of about 18°C (64°F) in the winter. Thunderstorms happen frequently; on average, 15 to 20 thunderstorms happen every year. The Great Victoria Desert is close to several other deserts: the Little Sandy and Gibson deserts lie to the north, while the Triari and Sturt Stony deserts are to the east.
The Sahara is Africa’s most famous desert and it potentially the most famous desert in the world. That means that the Kalahari, located in the southern portion of the African continent, gets relatively little attention. Even though it’s not as expansive or as well-known as its northern cousin, the Kalahari is impressive in its own right. Although only parts of the Kalahari can be classified as a “true” desert, receiving less than 10 inches of rain per year, the Kalahari is thought to cover around nearly 1 million km (or 350,000 miles). Its age is also impressive with geological studies showing it seems to date back to when the continent of Africa was formed, around 60 million years ago. Summers here reach extreme temperatures as daily temperatures sometimes soar to 45°C (113°F). The Kalahari is also notable for its characteristic red sands.
This expansive area in northern Chile is well-known for a number of reasons. First and foremost, the Atacama is known as the driest place on the planet. Straddling the area between 2 mountain ranges – the Andes and the Chilean Coastal mountains – the Atacama exists in a double-rain shadow, which excludes it from getting moisture from either the Pacific or Atlantic Oceans. It’s estimated that the Atacama has experienced this aridity for at least 3 million years (if not longer), making it the oldest continuously dry area on earth. Data suggests that from 1590 to 1971, the Atacama experienced no significant rainfall. These days, annual rainfall is about 15 mm (0.6 inches). The Atacama has long been compared to Mars and film and television producers are known to film Martian settings in this desert. NASA researchers have also used the Atacama as a test location.