Austral Zone

The Zona Austral (''Southernmost Zone'') is one of the five natural regions into which CORFO divided continental Chile in 1950 corresponding to the Chilean portion of Patagonia. It is surrounded by the Zona Sur and the Chacao Channel to the north, the Pacific Ocean and Drake's Passage to the south and west, and the Andean mountains and Argentina to the east. If excluding Chiloé Archipelago Zona Austral covers all of Chilean Patagonia.

Geography

Physical geography

In the far south (Chile Austral), which extends from Valdivia through the Chacao Channel to Cape Horn, the Andes and the South Pacific meet. This district of the country is mountainous, heavily forested and inhospitable. The deeply indented coastline is filled with islands which preserve the general outline of the continent southward to the Fuegian archipelago, the outside groups forming a continuation of the Chilean Coast Range. The heavy and continuous rainfall throughout this region, especially in the latitude of Chiloé, gives rise to a large number of rivers and lakes. Farther south this excessive precipitation is in the form of snow in the Andes, forming glaciers at a comparatively low level which in places discharge into the inlets and bays of the sea. The extreme southern part of this region extends eastward to the Atlantic entrance to the Strait of Magellan, and includes the greater part of the Isla Grande de Tierra del Fuego volcano southwards a well-defined western longitudinal valley, occupied by the Carretera Austral, divides the Andes into two chains, the eastern being the main chain, to which belong mounts Ventisquero Sur, Barros Arana and Alto Nevado, while the western chain, broken into imposing blocks, contains several high volcanic peaks such as Corcovado, Yanteles and Melimoyu.

An important transverse mountain range of the Andes separates the valleys of the rivers Simpson and Ibañez. This section is dominated by the active Hudson volcano and the jagged Cerro Castillo.

Southward from General Carrera lake is found a wide oblique opening in the range, through which flows the river Baker. The main chain of the Andes in the west is an enormous rugged mass of ice and snow of an average height of 2700 m (9000 ft.), sending glaciers to all the western fjords. Monte San Valentin (4,058 m 3,314 ft. is the culminating point of the Andes in the region extending from 49° to 46° S latitude Monte San Lorenzo, detached from the main chain of the Andes, is 3,706 m (12,156 ft.) high.

The section from 48° to 52° S latitude is a continuous ice-capped mountain range, and some of the glaciers extend from the eastern lakes to the western channels, where they reach the sea-level. The highest mountain in the section is Lautaro volcano, but the most famous compose the Cordillera del Paine in the south and the Fitz Roy and Cordillera Riesco, which are separated by the Fjord of the Mountains.

From the 52 deg. S. lat. up to Strait of Magellan, the western slope of the Cordillera does not, properly speaking, exist. Abrupt walls overlook the Pacific, and great longitudinal and transversal channels and fjords run right through the heart of the range, cutting it generally in a direction more or less oblique to its axis, the result of movements of the Earth's crust. This region is not fully explored, and all that is known of it is that it is principally composed of the same rocks as the Fuegian Andes, and that the greater part of its upper valleys is occupied by glaciers that reach down to the sea amid dense forest.

The Cordillera of the Andes in Tierra del Fuego is formed of crystalline schists, and culminates in the snow-capped peaks of Mount Darwin and Monte Sarmiento in the Cordillera Darwin, which contains glaciers of greater extent than those of Mont Blanc. The extent of the glaciers is considerable in this region, which, geographically, is more complex than was formerly supposed. Although, in the explored portion of the Fuegian chain, the volcanoes which have been mentioned from time to time have not been met with, there seem to have existed to the south, on the islands, many neo-volcanic rocks, some of which appear to be contemporaneous with the basaltic sheet that covers a part of eastern Patagonia.

Farther south the Andes terminates in Cape Horn. In this section the mountains are composed principally of crystalline rocks, and their heights are inconsiderable when compared with those of the northern Andes.

Coasts

The continental coastline features numerous inlets and fjords, from which the mountains seem to rise straight up to great elevations; this is, for example, the case with the Cerro Macá (2,300 meters) near Puerto Aisén. The rest of the land consists of literally thousands of islands forming numerous archipelagos interwoven with sometimes-narrow channels, which provide the main routes of navigation. The grouping of such islands shows that they are in part the summits of a submerged mountain chain, a continuation southward of the Chilean Coast Range. Three groups of these, called Chiloé, Guaitecas and Chonos archipelagoes, lie North of the Taitao Peninsula.

The largest island of this portion of Austral Chile is Chiloé, which is inhabited. Some of the smaller islands of these groups are also inhabited, though the excessive rainfall of these latitudes and the violent westerly storms render them highly unfavourable for human occupation. Some of the smallest islands are barren rocks, but the majority of them are covered with forests. These archipelagoes are separated from the mainland in the north by the gulfs of Ancud and Corcovado, 30 to 35 mi wide, which appear to be a submerged part of the great Chilean Central Valley, and farther south by the narrower Moraleda Channel, which terminates southward in a confusing network of passages between the mainland and the islands of the Chonos group.

Below the Taitao peninsula is the broad open Gulf of Penas, which carries the coast-line eastward fully 100 mi and is noticeably free from islands, with some exceptions. The northern entrance to Messier Channel is through this gulf. Messier, Pitt, Sarmiento and Smyth's Channels, which form a comparatively safe and remarkably picturesque inside route for ships, about 338 mi in length, separate another series of archipelagoes from the mainland. These channels are in places narrow and tortuous. Among the islands which thickly fringe this part of the coast, the largest are Merino Jarpa (lying within Baker Channel), Prat, Campana (part of Guayaneco Archipelago), Little Wellington, Wellington and Mornington (of the Wellington Archipelago), Madre de Dios, Duke of York, Chatham, Hanover, Cambridge, Contreras, Rennell and the Queen Adelaide Archipelago, a group of small barren rocks and islands lying immediately north of the Pacific entrance to the Strait of Magellan. The large number of English names on this coast is due to the fact that the earliest detailed survey of this region was made by English naval officers; the charts prepared from their surveys are still in use and form the basis of all subsequent maps.

Belonging to the Tierra del Fuego archipelago south of the Strait of Magellan are Desolación, Santa Inés, Clarence, Capitán Aracena, Dawson, Londonderry, Hoste, Navarino and Wollaston Islands, with innumerable smaller islands and rocks fringing their shores and filling the channels between them.

The far south contains large expanses of pastures that are best suited for raising sheep, mainly on Isla Grande de Tierra del Fuego

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