Chile divides into northern, central, and southern regions, with the great Andes mountain system common to all three.
Northern Chile consists largely of the desolate Atacama Desert, which stretches roughly 600 miles (1,000 km) southward from the Peru border and eastward from the Pacific coast into the foothills of the Andes. Lofty Andean peaks, some of which are volcanic, rise abruptly along the edge of the desert. Snowcapped Ojos del Salado, Chile's highest peak, reaches 22,572 feet (6,880 m) above sea level on the Argentina boundary.
Central Chile extends about 1,000 miles (1,600 km) from the southern edge of the Atacama Desert to the Corcovado Gulf. Much of the region is occupied by the Andes and the Cordillera de la Costa, a coastal mountain range. Between them is the Central Valley of Chile—the country's principal agricultural region and the home of most of its people. The valley lies some 300 to 2,300 feet (90 to 700 m) above sea level and is crossed by several spurs of the Andes. Central Chile usually suffers most during the country's frequent earthquakes.
Southern Chile is a rugged region with many islands and a fjorded coast where the Andes drop into the sea. The mountains here are lower than those in central or northern Chile. Although only a few peaks exceed elevations of 11,000 feet (3,350 m), there are extensive glaciers. Tierra del Fuego, an island group south of the Strait of Magellan, in the far south, is shared by Chile and Argentina.
With few exceptions, Chile's rivers begin in or near the Andes and drain westward into the Pacific. Many are used for irrigation, and some provide hydroelectric power. The longest, flowing 270 miles (435 km), is the Loa. It is the only river that crosses the Atacama Desert. Other rivers include the Bio-Bio, Maipo (Maipu), and Copiapo. North of the city of Puerto Montt lies a district of glacial mountain lakes known for their outstanding natural beauty.
Climate. Because of great differences in latitude and altitude, Chile has a variety of climates. Throughout the mountainous areas, temperatures steadily decrease as altitude increases, and at high elevations the climate is always cold.
In the Atacama Desert, temperatures are mild, mainly because of the influence of the cold Peru (Humboldt) Current offshore. It is one of the most arid deserts on earth; in places, no rainfall has ever been recorded.
Much of central Chile has a climate like that of southern California: dry, relatively hot summers and cool, rainy winters. In Santiago, for example, average temperatures are 69° F. (21° C.) in January and 46° F. (8° C.) in July. Rainfall averages 14 inches (360 mm) annually. Temperatures in the Central Valley are usually Chile's highest, occasionally reaching 100° F. (38° C.).
In southern Chile the climate is generally cool and rainy throughout the year, resembling that of the North American Pacific coast from Oregon to the Alaska Panhandle. Annual precipitation in certain highland areas of the south is extremely heavy, sometimes exceeding 200 inches (5,080 mm) a year. In the Patagonia section of Chile, which adjoins the eastern half of the Strait of Magellan, yearly rainfall is usually less than 20 inches (508 mm).
Chile's vegetation is as varied as its climates. The northern coastal desert is virtually barren. In the Central Valley are low evergreen bushes, scrubby trees, and cacti. Much of southern Chile and parts of mountain ranges in other regions are blanketed with forests of conifers, laurels, and other middle-latitude trees. Grasses predominate in Patagonia and on some mountain slopes.
Mountain lions (also called cougars and pumas), guanacos, vicunas, deer, and wolves are among Chile's mammals. There are many kinds of birds, including rheas, condors, pelicans, gulls, and penguins.