Top 10 deserts factsDeserts quiz
Welwitschia is known as the plant with the longest living leaves. How many leaves does it produce in its centuries-spanning lifetime?
Two. Welwitschia is endemic to the Namib desert. The age of individual plants is difficult to assess, but many plants may be over 1000 (or even 2000) years old. Because Welwitschia only produces a single pair of foliage leaves, the plant was thought by some to be neotenic, consisting essentially of a "giant seedling." However, research showed that its anatomy is not consistent with the giant seedling idea. Instead, the plant is more accurately thought of as achieving its unusual morphology as a result of having "lost its head" (apical meristem) at an early stage.
Why is White Sands Desert in New Mexico so purely white?
It is gypsum. White Sands, having 442 total square kilometers of dune fields, is the world's largest surface deposit of gypsum. Unlike other desert sands, it is cool to the touch, due to the high rate of evaporation of surface moisture and the fact that the sands reflect, rather than absorb, the sun's rays.
Which desert has this famous "eye"?
Sahara. The Richat Structure in Mauritania, also known as the Eye of the Sahara, was interpreted as an asteroid impact structure, but no evidence of shock metamorphism has been found. Today, scientists believe that it is a huge (40 km in diameter) and deeply eroded geologic dome.
Which (non-polar) desert is the driest in the world?
Atacama. The Atacama is the driest of all deserts, with some places having recorded no rain in living memory. It extends along the Pacific coast, forming a huge strip of arid, hostile beach. The average rainfall in the Antofagasta region is 1 millimeter (0.04 in) per year.
Where are such formations usually found?
In deserts. Desert rose is the colloquial name given to rosette formations of crystal clusters of gypsum or baryte which contain abundant sand grains. Desert roses occur when the crystals form in arid sandy conditions, such as the evaporation of a shallow salt basin.
Which is the world's oldest desert?
Namib Desert. The Namib is the oldest desert in the world. It is estimated to be up to 80 million years old. It stretches some 2,000 kms (1,200 mi) along the Atlantic coasts of Angola, Namibia, and South Africa.
Which continent has the lowest precipitation rate?
Antarctica is technically a desert, averaging just 166 mm (6.5 in) of precipitation per year. Only some fringe coastal areas have a tundra climate with a short summer, averaging above freezing, and much higher precipitation.
What are the circular objects visible on this satellite photo taken over Libya?
Agricultural fields. This is an astronaut photo of the Al Khufrah Oasis in Libya. The circular shape of fields is characteristic of center pivot irrigation. These fields are approximately 0.6 mile (1 kilometer) in diameter. Lighter colors indicate fields that have been harvested recently or just planted.