We all know that we live in a desert—or do we? Well, it seems that it depends on how you define desert, and some geographers characterize the Chihuahuan Desert as semi-arid rather than true desert. Most geographers, though, do recognize the region as desert. Admittedly, though, there are much more extreme deserts than ours. After all, much of our desert gets over 8 inches of precipitation a year. Compare that with the Atacama Desert, in northern Chile. Average precipitation is said to be about 0.004 inches per year, and some places are thought to have not had rain for over 400 years!
Of course, many people haven't heard of the Atacama Desert, but
virtually everybody knows of the Sahara—and rightly so, for this is the
world's largest desert, about the size of the United States. The Sahara averages
less than 3 inches of rain a year. Perhaps the best way to visualize the arid lands of
the earth is from space. The vast expanses of landscapes void of the slightest hint of
green tells it all.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Northern Africa and Europe at sunset. The Sahara is clearly visible as the vegetationless light-colored region covering most of northern Africa. NASA photo from the last voyage of the Columbia. The large, white mass in the upper left corner is Greenland; Iceland is clearly visible between Greenland and the British Isles. Photograph courtesy of NASA.
California Academy—Sahara