Tronador ( es, Cerro Tronador) is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and per ...

in the southern

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

, located along the border between

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, near the Argentine city of

Bariloche San Carlos de Bariloche, usually known as Bariloche (), is a city in the province of Río Negro Province, Río Negro, Argentina, situated in the foothills of the Andes on the southern shores of Nahuel Huapi Lake. It is located within the Nahuel ...

. The mountain was named ''Tronador'' ( Spanish for "Thunderer") by locals in reference to the sound of falling

serac A serac (from Swiss French ''sérac'') is a block or column of glacial ice, often formed by intersecting crevasses on a glacier. Commonly house-sized or larger, they are dangerous to mountaineers, since they may topple with little warning. Even ...

s. With an altitude of , Tronador stands more than 1,000 m above nearby mountains in the Andean massif, making it a popular mountaineering destination. Located inside two national parks,

Nahuel Huapi Nahuel Huapi National Park () is the oldest national park in Argentina, established in 1934. It surrounds Nahuel Huapi Lake in the foothills of the Patagonian Andes. The largest of the national parks in the region, it has an area of , or nearly ...

in Argentina and

Vicente Pérez Rosales Vicente Pérez Rosales (; 5 April 1807 – 6 September 1886) was a politician, traveller, merchant, miner and Chilean diplomat that organised the colonisation by Germans and Chileans of the Llanquihue area. Vicente Pérez Rosales National Park ...

in Chile, Tronador hosts a total of eight

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

s, which are currently retreating due to warming of the upper

troposphere The troposphere is the first and lowest layer of the atmosphere of the Earth, and contains 75% of the total mass of the planetary atmosphere, 99% of the total mass of water vapour and aerosols, and is where most weather phenomena occur. From ...

.Bown, Francisca. 2004. Cambios climáticos en la Región de Los Lagos y respuestas recientes del Glaciar Casa Pangue (41º08’S). Tesis para optar al grado de Magíster en Geografía. Universidad de Chile.

Geography and geology

Cerro Tronador is in the

Wet Andes file:Andes_clima.png, 200px, Map of the climatic regions of the Andes. The Wet Andes are shown in dark blue. The Dry Andes are shown in yellow and the Tropical Andes in green. The Wet Andes ( es, Andes húmedos) is a climatic and glaciology, glacio ...

, a zone of high precipitation of both snow and rain. The humid temperate climate of the southern Andes has allowed several glaciers to develop due to high

accumulation Accumulation may refer to: Finance * Accumulation function, a mathematical function defined in terms of the ratio future value to present value * Capital accumulation, the gathering of objects of value Science and engineering * Accumulate (highe ...

rates. Most of the precipitation is produced by western frontal systems from the Pacific. Located in the middle of the Andean massif at a latitude of 41° S, Tronador is part of an alpine landscape of

fjord In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Germany, Greenland, the Faroe Islands, Ice ...

glacial lake A glacial lake is a body of water with origins from glacier activity. They are formed when a glacier erodes the land and then melts, filling the depression created by the glacier. Formation Near the end of the last glacial period, roughly 10,0 ...

s, and U-shaped valleys. The forming of the landscape took place during the

Quaternary glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma (million years ago) and is ongoing. Although geologists describe ...

s, periods during which the whole area was covered by the Patagonian Ice Sheet. The volcano grew during the glacials and

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene in ...

s of the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

but became practically extinct in the late Middle Pleistocene, approximately 300 ka ago, due to a shift in the active front of the

Southern Volcanic Zone The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American ...

to which it belongs.Mauricio Mella, Jorge Muñoz, Mario Vergara,Erik Klohn, Lang Farmer, Charles R. Ster
Petrogenesis of the Pleistocene Tronador Volcanic Group, Andean Southern Volcanic Zone
Revista Geológica de Chile Since then, glaciations and other erosive processes shaped the mountain freely without new output of

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

tephra Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they rem ...

. As in the case of nearby Lanín volcano, Tronador is composed mostly of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

s, and has seen a decline in activity as the Osorno and

Calbuco Calbuco is a city and commune in southern Chile administered by the Municipality of Calbuco. Administratively Calbuco belongs to the Llanquihue Province of Los Lagos Region. The origin of the city was the Spanish Fort Calbuco founded in 1603, an ...

volcanoes grow further west.

Glaciers

Tronador is notable for the many glaciers covering parts of its flanks. Up to eight glaciers have been inventoried: Alerce, Ventisquero Negro, Casa Pangue, Castaño Overa, Río Blanco, Frías, Peulla, and Manso. Over the last decades the glaciers on Tronador, like the majority of southern Andean glaciers, have been retreating. The Casa Pangue glacier on the northwestern side of Tronador experienced a thinning between 1961 and 1998, with an increased rate of retreat between 1981 and 1998 at 52 m a⁻¹. The retreat and thinning is attributed to a decrease in precipitation and a warming of the upper

over the last several decades.

Alerce Glacier Tronador ( es, Cerro Tronador) is an extinct stratovolcano in the southern Andes, located along the border between Argentina and Chile, near the Argentine city of Bariloche. The mountain was named ''Tronador'' (Spanish for "Thunderer") by locals ...

, on the Argentinian side, can be visited from Refugio

Otto Meiling Otto Meiling (1902–1989) was a German-born mountaineer who achieved many first ascents in Nahuel Huapi National Park and the surrounding area. Meiling left Bavaria for Buenos Aires in his early twenties, working as a labourer, learning the ...

, a mountain hut that is sandwiched between it and Castaño Overa Glacier. Castaño Overa, also on the Argentinian side, is smaller and relatively accessible by hike from Pampa Linda. Guided trekking tours allow visitors to cross Castaño Overa or walk to Tronador's peak. Ventisquero Negro ("black snowdrift" in Spanish) is a rather unusual glacier at the base of Tronador in Nahuel Huapi National Park. Its unusual dark brown colour comes from dirt and sediment picked up in the glacier's accumulation zone, which is fed by the Río Manso Glacier several hundred metres higher up the mountain. Brown icebergs calve from the glacier and then float in a small lake until eventually melting.

Peaks

According to the Aoneker map, these are the named peaks on Tronador: Anon or Internacional (3484m), Argentino (3187), Chileno (3262), and Torre Ilse (2585). Named ridges include Filo Sur (3054), Filo Blanco (3146), Filo La Vieja (2715), and Filo Lamotte (2340).

Mountaineering and tourism

Tronador was first climbed by Hermann Claussen solo on 29 January 1934, after several attempts. A

mountain hut A mountain hut is a building located high in the mountains, generally accessible only by foot, intended to provide food and shelter to mountaineers, climbers and hikers. Mountain huts are usually operated by an Alpine Club or some organization d ...

, Refugio

, is the destination of popular day hikes on the mountain, and is named after a German mountaineer who made dozens of ascents and spent years guiding people around it. The hut is located about 1200m vertically above Pampa Linda, at the mountain's base. Most summers the Internacional or Anon peaks (the highest of Tronador's three peaks) is climbable. However, an unusually hot summer increased rockfall to dangerous levels during January and February 2008. The Argentine side risks becoming no longer accessible due to increasingly warm weather in the region destabilising the glaciers.

Gallery

File:Tronador from Pampa Linda Stevage.jpg, Seen from Pampa Linda. File:Cerro Tronador - cordillera de los Andes.JPG File:Glacier Alerce Stevage.jpg, Alerce Glacier, one of Tronador's 7 glaciers.

References