The Planchón-Peteroa-Azufre volcanic complex is located about 70 kilometers from Curicó and bordered by Argentina. This complex represents one of the most striking mountain phenomena in the central Andes.
In the complex’s areas, there are several mountain glaciers, which initiate important rivers: concerning Chilean territory, the Claro river links later to the Teno river in Los Queñes (the closer town) and with a part of the Colorado river’s basin. On the Argentinean side, the Valenzuela river transforms into the Grande river.
This complex is the northernmost of volcanoes from the Maule region, where there are the extinct Azufre and the Peteroa volcanoes. The Planchón volcano is rebuilt over them and has several craters and similar structures at the top.
According to historical precedents, this Planchón–Peteroa complex is very active. There is a high risk of causing lahars if some eruption eventually comes, due to the extensive ice cover distributed in the Azufre area. This is a hazard for living beings in rivers that feed those glaciers already mentioned.
Planchón–Peteroa volcanic complex / © Gerald Prins (April 2015).
Glaciers in Planchón–Peteroa volcanic complex and their importance
View of the volcanic complex and the Peñón Norte glacier from the top of the Azufre 1 volcano/ © Nicolás Méndez (January 2012).
This complex collects a vast frozen-ice volume distributed in twelve mountain glaciers, six glaciarets, and four covered glaciers, resulting in approximately 15.11 km² in January 2019. According to those figures, Argentina has 6.3 km² of that amount, while Chile has 8.81 km².
Glacier covered by ashes in Peteroa volcano / © Juan Esteban Berrio (February 2019).
The Eastern slope of Peteroa volcano is covered by the glacier.
March 2008 (above) – © Ing. Alvin / Mach 2018 (below) – © Luis Faundez.
Hanging glacier in crater 1 post-eruption of the Peteroa volcano in 2010 / © Cristobal Bayer Monnard (March 2011).
Peñón Norte and Sur glacier in March 2008 / © Ing. Alvin (April 2018) / © Juan Esteban Berrio.
Hanging glacier El Azufre or PPA4 in Chilean territory / © DGA (December 2013).
Continuous retreat
This diagram demonstrates the evident retreat in the volcanic complex, where the Peteroa volcano has an area loss of 75% from 1985 to 2011 / © Juan Esteban Berrio.
Among the summits of the Azufre volcano, five mountain glaciers detach from a hill. Two of them are located on the Argentinean side, named as Peñón Norte and Peñón Sur glacier. On the Chilean side, there are no official names, although the study of glacier variations – made by the Center for Scientific Studies (CECs according to Spanish initials) in 2011 – denominated them as PPA2 y PPA3. Both glaciers visually have a similar and continued retreat over time. The Peñón Norte glacier had an area of 2.45 km², which has decreased to 1.86 km² approximately. The front has retreated around 450 m by the north side, while the south is 187.3 m. Finally, the study exposes an annual loss of the glacier volume of 49.6 m in the north and 20.8 m in the south limit / © Juan Esteban Berrio.
Moreover, the Peñón Sur glacier used to cover an area of 1.44 km², but nowadays it just covers 1km², unfortunately.
We already had the premise about the constant retreat – and as we had said – it’s more intense the glacier loss on the Peteroa volcano, showing a significantly bigger loss than its neighbor, as demonstrated in the diagram / © Juan Esteban Berrio.
Eventual future complications
The volcano complex has experienced a substantive glacier loss during these last years. Several complications would affect both countries because, as we know, these frozen bodies are tributaries of rivers that provide us with the vital components downstream. Not only the volcanic activity might cause important natural events but also the glacier loss around it, affecting the fragile ecosystem and impacting glaciers settled in different mountainsides.
The complex is outside a protected area; it doesn’t belong in a National Park, Nature Reserve, Natural Monument, or Nature Sanctuary category. Another important aspect is that the complex is exempt from mining activity so far. However, the complex’s retreats are more evident, according to satellite images. The accelerated defrosting is a clear consequence of warmer summers and less cold winters that hold back the same snow accumulation as earlier periods.
Chile gets its freshwater supply mostly from the Chilean Andes and has 11% of the glaciers globally. We are privileged, but, at the same time, spectators of these natural changes, which are increased by our economic system and lifestyle, even though sometimes those aspects aren’t considered in the development.
Unfortunately, even though a law that protects glaciers would exist, the melting cannot be stopped. However, it would help to protect some of them that are irrationally invaded and not considered a sustainable future.
References:
- Complejo Volcánico Planchón-Peteroa pdf. [Planchón-Peteroa volcanic complex]. Link
- Andeshandbook. Link
- Inventario de glaciares chilenos, Dirección General de Aguas (DGA) [Chilean glaciers inventory, General Water Authority]. Link
- Inventario de glaciares de la hoya del río Mataquito [Glaciers inventory about Mataquito river plain] / Carlos Noveroy C.; Ministery of Public Works, Dirección General de Aguas (DGA) [General Water Authority] 1987.
- Chilean Glaciers / Ministery of Public Works, Dirección General de Aguas, Unidad de Glaciología y Nieves [General Water Authority, Glaciology and Snow Department] 2014.
- Inventario Nacional de Glaciares [National inventory of Glaciers], Argentina, 2018. Subcuenca del rio Grande sector Norte [Sub-basin of Grande river North sector]. Link
- ¿Qué está pasando con los glaciares del CV Planchón – Peteroa? [What is happening with glaciers of the Planchón-Peteroa volcanic complex?] Pitte P. et al. Link
- Variaciones recientes de glaciares en Chile, según principales zonas glaciológicas, [Current variations about glaciers in Chile, according to main glaciological areas] Center for Scientific studies (CECs) 2011.
- Laboratorio de Glaciología Chile [Glaciology Laboratory of Chile]. Link
Featured image:
- Planchón-Peteroa volcanic complex, Maule region, Chile / © Juan Berrío. Link ubicación
