Thursday, December 2, 2010

Principal Deserts of the World

Principal Deserts of the World

Deserts are arid regions, generally receiving less than ten inches of precipitation a year, or regions where the potential evaporation rate is twice as great as the precipitation.
The world's deserts are divided into four categories. Subtropical deserts are the hottest, with parched terrain and rapid evaporation. Although cool coastal deserts are located within the same latitudes as subtropical deserts, the average temperature is much cooler because of frigid offshore ocean currents. Cold winter deserts are marked by stark temperature differences from season to season, ranging from 100° F (38° C) in the summer to 10° F (–12° C) in the winter. Polar regions are also considered to be deserts because nearly all moisture in these areas is locked up in the form of ice.
 
DesertLocationSizeTopography
SUBTROPICAL DESERTS
SaharaMorocco, Western Sahara, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Niger, Chad, Ethiopia, Eritrea, Somalia3.5 million sq. mi.70% gravel plains, sand, and dunes. Contrary to popular belief, the desert is only 30% sand. The world's largest nonpolar desert gets its name from the Arabic word Sahra', meaning desert
Arabian Saudi Arabia, Kuwait, Qatar, United Arab Emirates, Oman, Yemen1 million sq. mi.Gravel plains, rocky highlands; one-fourth is the Rub al-Khali (“Empty Quarter”), the world's largest expanse of unbroken sand
Kalahari Botswana, South Africa, Namibia220,000 sq. mi.Sand sheets, longitudinal dunes
Australian Desert
   
 GibsonAustralia (southern portion of the Western Desert)120,000 sq. mi.Sandhills, gravel, grass. These three regions of desert are collectively referred to as the Great Western Desert—otherwise known as “the Outback.” Contains Ayers Rock, or Uluru, one of the world's largest monoliths
 Great SandyAustralia (northern portion of the Western Desert)150,000 sq. mi.
 Great VictoriaAustralia (southernmost portion of the Western Desert)250,000 sq. mi.
 Simpson and
  Sturt Stony
Australia (eastern half of the continent)56,000 sq. mi. Simpson's straight, parallel sand dunes are the longest in the world—up to 125 mi. Encompasses the Stewart Stony Desert, named for the Australian explorer
Mojave U.S.: Arizona, Colorado, Nevada, Utah, California54,000 sq. mi.Mountain chains, dry alkaline lake beds, calcium carbonate dunes
SonoranU.S.: Arizona, California; Mexico120,000 sq. mi.Basins and plains bordered by mountain ridges; home to the Saguaro cactus
ChihuahuanMexico; southwestern U.S.175,000 sq. mi. Shrub desert; largest in North America
TharIndia, Pakistan175,000 sq. mi.Rocky sand and sand dunes
COOL COASTAL DESERTS
NamibAngola, Namibia, South Africa13,000 sq. mi.Gravel plains
AtacamaChile54,000 sq. mi.Salt basins, sand, lava; world's driest desert
COLD WINTER DESERTS
Great BasinU.S.: Nevada, Oregon, Utah190,000 sq. mi.Mountain ridges, valleys, 1% sand dunes
Colorado PlateauU.S.: Arizona, Colorado, New Mexico, Utah, Wyoming130,000 sq. mi.Sedimentary rock, mesas, and plateaus—includes the Grand Canyon and is also called the “Painted Desert” because of the spectacular colors in its rocks and canyons
PatagonianArgentina260,000 sq. mi.Gravel plains, plateaus, basalt sheets
Kara-Kum
Uzbekistan, Turkmenistan135,000 sq. mi.90% gray layered sand—name means “black sand”
Kyzyl-Kum Uzbekistan, Turkmenistan, Kazakhstan115,000 sq. mi.Sands, rock—name means “red sand”
IranianIran100,000 sq. mi.Salt, gravel, rock
TaklamakanChina105,000 sq. mi.Sand, dunes, gravel
GobiChina, Mongolia500,000 sq. mi.Stony, sandy soil, steppes (dry grasslands)
POLAR
ArcticU.S., Canada, Greenland, Iceland, Norway, Sweden, Finland, Russia5.4 million sq. mi.Snow, glaciers, tundra
AntarcticAntarctica5.5 million sq. mi.Ice, snow, bedrock
Fact Monster/Information Please® Database, © 2007 Pearson Education, Inc. All rights reserved.

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