The country’s provinces are divided in 7 zones regarding climate and terrain. From North to South, West to East:

• Argentine Northwest: Jujuy, Salta, Tucumán, Catamarca, La Rioja
• Gran Chaco: Formosa, Chaco, Santiago del Estero
• Mesopotamia: Misiones, Corrientes
• Central: Córdoba, Entre Ríos
• Cuyo: San Juan, Mendoza, San Luis
• The Pampas: Santa Fe, La Pampa, Buenos Aires
• Patagonia: Rio Negro, Neuquén, Chubut, Santa Cruz, Tierra del Fuego

Geology

Argentina is situated between the Andes in the west and the southern Atlantic Ocean in the east.

Terrain

Argentinean Andes

The Argentinean Andes contain some of the tallest mountains in South America, including Cerro Bonete 6,872, Ojos del Salado 6,893 m, Cerro Mercedario 6,768 m, and Cerro Aconcagua, which at 6,960 m is the tallest peak on the continent and in the entire Western Hemisphere. Both of these peaks are located near the Chile border southwest of San Juan.

The Andes region is also home to arid basins, lush foothills covered with grape vineyards, glacial mountains, and half of the Los Lagos Region (Lake District) (the other half is in Chile).

The Lake District, named for the many glacial lakes carved out of the mountains and subsequently filled by melt-water and rain, is located in the southern Andes and boasts a diverse natural landscape of glaciers, native old growth forests, lakes, rivers, fjords, volcanoes, and sentinel mountains.

Throughout the Andes that separate Chile and Argentina there are more than 1,800 volcanoes, 28 of which are considered to be active. These account for approximately one-fifth of the Earth’s active volcanoes.

Patagonia

Patagonia, the southern region of Argentina, is a combination of pastoral steppes and glacial regions. Located in this region near the Chilean border is Parc Nacional Los Glaciares (Glacier National Park ), where some 300 glaciers make up part of the Patagonian Ice Cap (21,760 km2). The ice cap, flowing into the Pacific oceans from the Andes, is the largest in the Southern Hemisphere outside of Antarctica.

Thirteen of the glaciers feed lakes in the region. The Upsala glacier, at 60 km long and 10 km wide, is the largest in South America and can only be reached by boat, since it floats in Lago Argentino. The next largest is the 4.8 km wide Perito Moreno, which stretches about 35 km to Lago Argentino, where it forms a natural dam in the lake. Jagged mountain peaks formed from granite include Cerro Fitz Roy 3,405 m, Cerro Torre 3,102 m, and Cerro Pináculo 2,160 m.

Smaller mountain ranges also exist in central South America. These ranges cut across the center of the country and serve as the divider between the southern Patagonia region and the northeastern Pampas. From west to east these ranges are the Sierra Lihuel-Calel, the Sierra de la Ventana, and the Sierra del Tandil.

Plateaus

The Somuncurá Plateau is a basalt plateau with alternating hills and depressions. It stretches across the Río Negro and Chubut provinces, or the area from the Chubut River north to the Negro River. The region undergoes severe climate changes between the winter and summer months. The area has lava formations and contains many fruit and alfalfa plantations. Cattle ranchers find this area to be ideal for raising their livestock.

A smaller plateau, the Atacama Plateau, occupies the region just east of the Andes Mountains in northern Argentina and extends east to the city of San Miguel de Tucumán.

Hydrography

Water Resources

Water resources management (WRM) functions in Argentina are handled by multiple institutions operating at the national, provincial, and river basin level, with a variety of functions and jurisdictions.

On the national level, the National Institute for Water and the Environment (INA) and the National Water and Sanitation Utility (AySA) are charged with the duties of researching, water resources preservation, developing services, and implementing water projects.

Rivers

Except in the Northeast there are few large rivers, and many have only seasonal flows. Nearly all watercourses drain eastward toward the Atlantic, but a large number terminate in lakes and swamps or become lost in the thirsty soils of the Pampas and Patagonia.

The four major rivers systems are those that feed into the Río de la Plata estuary, those made up of the Andean streams, those of the central river system, and those of the southern system.

The Paraná, the second-longest river in South America after the Amazon, flows approximately 4,900 km and forms part of the borders between Brazil and Paraguay, and Paraguay and Argentina. Its upper reaches feature many waterfalls.

It is joined by the Iguazú River (Río Iguaçu) where it enters Argentina in the northeast. This area is well known throughout the world for the spectacular Iguazú Falls (Cataratas Iguaçu, meaning “great water”). One of the world’s great natural wonders, they are located on the border between Argentina and Brazil with two-thirds of the falls in Argentina. They include approximately 275 falls, ranging between 60 and 80 m high. These falls are higher and wider than Niagara Falls on the border of the United States and Canada.

Other tributaries of the Paraná, which feed in from the west, are the Bermejo, Bermejito, Salado, and Carcarañá.

The Uruguay River 1,600 km forms part of the borders between Argentina and Brazil and Argentina and Uruguay. It is navigable for about 300 km from its mouth to Concordia.

The 2,550 km Paraguay River forms part of the border between Paraguay and Argentina, and flows into the Paraná north of Corrientes and Alto Paraná.

These all join to flow into the Río de la Plata, and eventually into the Atlantic Ocean in northern Argentina. Where these rivers meet, a wide estuary is formed, which can reach a maximum width of 222 km.

In north central Argentina, Lake Mar Chiquita is supplied with its water by several rivers. The Dulce River originates near San Miguel de Tucumán and flows southwest into the lake. From the southwest it is also fed by the Primero and Segundo Rivers.

In the northern Patagonia region, the major rivers are the Colorado and Negro Rivers, both of which rise in the Andes and flow to the Atlantic Ocean.

The Colorado is fed by the Salado River, which flows from Pico Ojos del Salado in a southeasterly direction to the Colorado. Tributaries of the Salado include the Atuel, Diamante, Tunuyán, Desaguadero, and the San Juan, all of which originate in the northwest Andes.

The Negro also has two main tributaries of its own, the Neuquén and the Limay. In the central Patagonia region the Chubut rises in the Andes and flows east to form a sizable lake before making its way to the ocean.

The Lake District is also coursed by its share of rivers, all originating in the mountains and flowing to the Atlantic. These include the Deseado, Chico, Santa Cruz, and Gallegos Rivers.

Lakes

The Los Lagos Region (Lake District), on the border of Chile and Argentina in the Andes mountain region, contains many glacial lakes that are carved out of the mountains then filled by melt-water and rain.

The most significant of these is Lago Buenos Aires, also known as General Carrera, located in southern Argentina and shared with Chile. It is the largest lake in the country and the fifth largest in all of South America with an average surface area of 2,240 km2.

Moving south along the border one would encounter Lago San Martín, Lago Viedma, and finally Lago Argentino, the second largest lake in this region with an area of 1466 km2.

Not far from Lake Buenos Aires on the Castillo Plain near Comodoro Rivadavia is Lake Colhue Huapi.

One of the world’s largest salt lakes, and the second largest lake in Argentina, is Lake Mar Chiquita (Little Sea), located in central Argentina. Its surface area varies from year to year and season to season, but has in it wettest periods spanned 5,770 km2.

The reservoir created by the Chocón dam, located on the Río Negro, is one of the country’s largest manmade lakes.

Wetlands

Iberá, in the northeast of Argentina, is a biologically rich region, with more than sixty ponds joined to marshes and swampland. The area is extremely humid, and is home to hundreds of bird species and thousands of insects, including a wide variety of butterflies.

The area hosts a diverse array of flora and fauna, notably the royal water lily, silk-cotton trees, alligators, and capybara, the largest rodent species in the world.