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 desertsare 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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
COOL COASTAL DESERTS | |||
Namib | Angola, Namibia, South Africa | 13,000 sq. mi. | Gravel plains |
Atacama | Chile | 54,000 sq. mi. | Salt basins, sand, lava; world's driest desert |
COLD WINTER DESERTS | |||
Great Basin | U.S.: Nevada, Oregon, Utah | 190,000 sq. mi. | Mountain ridges, valleys, 1% sand dunes |
Colorado Plateau | U.S.: Arizona, Colorado, New Mexico, Utah, Wyoming | 130,000 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 |
Patagonian | Argentina | 260,000 sq. mi. | Gravel plains, plateaus, basalt sheets |
Kara-Kum | Uzbekistan, Turkmenistan | 135,000 sq. mi. | 90% gray layered sand—name means “black sand” |
Kyzyl-Kum | Uzbekistan, Turkmenistan, Kazakhstan | 115,000 sq. mi. | Sands, rock—name means “red sand” |
Iranian | Iran | 100,000 sq. mi. | Salt, gravel, rock |
Taklamakan | China | 105,000 sq. mi. | Sand, dunes, gravel |
Gobi | China, Mongolia | 500,000 sq. mi. | Stony, sandy soil, steppes (dry grasslands) |
POLAR | |||
Arctic | U.S., Canada, Greenland, Iceland, Norway, Sweden, Finland, Russia | 5.4 million sq. mi. | Snow, glaciers, tundra |
Antarctic | Antarctica | 5.5 million sq. mi. | Ice, snow, bedrock |
0 comments :
Post a Comment