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Central Andes volcanic landscapes at the NASA Earth Observatory 9 September 2010

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Volcanic Landscapes, Central Andes : Image of the Day

At the NASA Earth Observatory there’s a spectacular astronaut photograph taken on 22 August 2010 of part of the volcanic landscape of the central Andes, on the border between Chile and Argentina. Among the volcanoes visible are Cerro el Cóndor, Peinado and Nevado Ojos del Salado, the world’s highest active volcano with a summit 6,887 metres a.s.l. This is a highly active volcanic region and the image reveals a fascinating and complex landscape of volcanic creation and erosive destruction, which is expertly discussed in the accompanying NASA caption.

NASA Earth Observatory: Volcanic landscapes, central Andes (Image of the Day, 6 September 2010)

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Planchón-Peteroa activity: a new bulletin from SERNAGEOMIN 8 September 2010

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Planchón-Peteroa: aerial view towards the east, showing the arrangement of the craters, the currently active south-western crater and deposits of ash on the icecap and snow. SERNAGEOMIN image, taken on 7 September 2010.

The Chilean state geological service SERNAGEOMIN has issued a new bulletin today on the activity at Planchón-Peteroa, reporting the outcome of an overflight of the volcanic complex which took place yesterday:

On the basis of the overflight of the area of the Planchón-Peteroa volcanic complex carried out on 7 September by SERNAGEOMIN personnel it can be concluded that Planchón volcano is maintaining eruptive activity with weak explosions, possibly of phreatomagmatic origin, similar to minor phases of the eruption recorded in 1991.

The currently active crater is the south-western, which has for several years usually shown persistent fumarolic activity.

The current eruptive activity shows local accumulations of ash in the area within 10 km of the volcano and no alterations have been observed in the glaciers of the volcanic complex.

The activity is described as consisting of ‘discrete pulses of gases and fine ash with a frequency of between 40 and 60 seconds’. These emissions create a ‘weak eruptive column of grey colour’ rising up to 200 metres above the crater, which then disperses towards Argentine territory, to the east of the volcano. The current activity at Planchón-Peteroa, according to SERNAGEOMIN, does not present a hazard to the local population, but continuous monitoring of the volcano will be carried out for as long as the activity continues. Planchón-Peteroa is currently at ‘alert level 4 Yellow’.


Planchón-Peteroa: aerial view towards the south-east, showing the western flank of the Planchón (north)-Peteroa (south) volcanic complex, with prominent ash deposits on the icecap and snow. SERNAGEOMIN image, taken on 7 September 2010.


Planchón-Peteroa: aerial view towards the east, showing the low altitude of the eruption column and the plume dispersing towards the east-south-east, over Argentine territory. SERNAGEOMIN image, taken on 7 September 2010.

Information
Global Volcanism Program: Planchón-Peteroa – summary information for Planchón-Peteroa (1507-04=)

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Chile: increased activity at Planchón-Peteroa 8 September 2010

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Planchón-Peteroa volcano is in central Chile, on the Chile-Argentina border. The complex history of this stratovolcano has produced the present-day nested group of three volcanoes: Azufre, Planchón and Peteroa. All historical eruptive activity has originated from Peteroa – there have been several explosive eruptions of VEI=1 and VEI=2 since the 1870s. Recent fumarolic activity in 2006, 2008 and 2010 underlines that this is very much a restless active volcano.

Reports from Chile indicate that Planchón-Peteroa’s activity is currently increasing and becoming more explosive; on 4 September an Argentine Air Force flight apparently encountered ‘a column of gas and ashes’ reaching up to two kilometres altitude, and the Air Force has also said that an area of 120 square kilometres around the volcano is being affected by ashfall. The Chilean state geological service SERNAGEOMIN issued a bulletin yesterday reporting a change in the activity of Planchón-Peteroa, from its habitual fumarolic venting to ‘eruptive activity’, albeit ‘minor up to now’:

Currently and from a technical point of view, the volcano is changing to moderately explosive eruptive activity, with a phreatic-vulcanian component (solid material) in the acid lakes of the crater zone.

Occasionally during 6 September an eruption column of pyroclasts and gases was observed, black in colour, which reached up to 1,200 metres above the crater zone, with a dispersal plume reaching at least 30 kilometres in length, mostly towards the east and, in a small percentage, to the north and south.

The bulletin notes that a ‘rock-fracturing’ earthquake of magnitude 5.2 at a depth of 13.4 kilometres was recorded on 6 September some 9 kilometres south-east of the volcanic complex. SERNAGEOMIN will be installing a seismological network and working with other Chilean agencies to maintain a full programme of monitoring at Planchón-Peteroa.

There have been suggestions that the current activity may have been sparked by the February 2010 Chilean earthquake (Erik has more on this at Eruptions), which is not the first time an earthquake has been put forward as a possible cause of eruptive activity at Planchón-Peteroa: Watt, Pyle and Mather (2009) suggest (in their Table 2) that an eruption of this volcano in July 1960 may have been triggered by the earthquake of May 1960. Watt et al argue that the incidence of volcanic eruptions in the aftermath of large earthquakes is signficant enough to justify the conclusion ‘that seismic eruption triggering following large earthquakes, with delays of several months, is a significant process in volcanic arcs’ without it being possible to pin down individual eruptions as being the result of particular earthquakes, and certainly it is not possible to say that the 2010 earthquake is responsible for the current activity at Planchón-Peteroa, any more than the same could be said for 1960. There is just not enough evidence to make a solid connection, and anyone who jumps right in with a declaration that big earthquakes = more volcanic eruptions is going way too far, but it’s an important and very interesting line of research; given the complex tectonic context of Planchón-Peteroa there is clearly much more work to be done before a clear conclusion can be reached.

[Thanks to Guillermo for pointing me to Planchón.]

References
José Cembrano & Luis Lara, ‘The link between volcanism and tectonics in the southern volcanic zone of the Chilean Andes: a review’, Tectonophysics, vol. 471, issues 1-2 (9 June 2009), pp. 96-113. [doi:10.1016/j.tecto.2009.02.038]
Daniel R. Tormey, Frederick A. Frey & Leopoldo Lopez-Escobar, ‘Geochemistry of the Active Azufre—Planchon—Peteroa Volcanic Complex, Chile (35°15′S): Evidence for Multiple Sources and Processes in a Cordilleran Arc Magmatic System’, Journal of Petrology, vol. 36, no. 2 (April 1995), pp. 265-298. [doi: 10.1093/petrology/36.2.265]
Sebastian F. L. Watt, David M. Pyle & Tamsin A. Mather, ‘The influence of great earthquakes on volcanic eruption rate along the Chilean subduction zone’, Earth and Planetary Science Letters, vol. 277, issues 3-4 (30 January 2009), pp. 399-407. [doi:10.1016/j.epsl.2008.11.005]

News
Entró en actividad el volcán Peteroa, en la frontera entre Mendoza y ChileLa Capital, 6 September 2010
Preocupa actividad de volcán PeteroaLa Estrella de Concepcion, 6 September 2010
Región del Maule: Sernageomin detecta actividad irregular en volcán Planchón y monitorea el Peteroa – Radio Bío-Bío, 7 September 2010
Planchon volcano starts spewing rocks, gases, Chile’s geology service says – Bloomberg, 7 September 2010
Volcán Planchón entró en actividad eruptiva en la Región del MauleEl Mercurio, 8 September 2010

Information
Global Volcanism Program: Planchón-Peteroa – summary information for Planchón-Peteroa (1507-04=)

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Emissions from Villarrica? 7 September 2010

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Buenos Aires VAAC (home page; message archive) issued three advisories on 4 and 5 September 2010 reporting emissions from Villarrica volcano in Chile: on 4 September a thin ash plume, very light, was identified extending 60 nautical miles NE of the volcano (4 September 2130Z), and on 5 September continuous emission was reported, although it was noted that low clouds were hampering observations (5 September 0500Z). In each case the source of the information was GOES-12 satellite data. No further reports have been issued, and this activity remains unconfirmed.

(The Villarrica Visual Observation Project have a live webcam for Villarrica. There are also four Villarrica webcams accessible from the Observatorio Volcanológico de los Andes del Sur home page, although they do not always show up-to-date images.)

[If you are baffled by the language of Volcanic Ash Advisories, try our easy-to-understand guide to How to read a Volcanic Ash Advisory.]

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Two years on at Chaitén 2 May 2010

Posted by admin in Chaitén, Chile, eruptions, volcanoes.
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View of Chaitén caldera and lava dome before the May 2008 eruption, © Eric Manríquez
View of Chaitén caldera and lava dome before the May 2008 eruption (© Eric Manríquez).

The eruption of Chaitén volcano in southern Chile began two years ago today, on 2 May 2008. Since that date eruptive activity at the volcano has continued uninterrupted: the intensity has varied, but the activity has never ceased.

View from May 2009 of the dome complex (courtesy Mr Javier Romero, Vialidad MOP, Puerto Montt)
View from May 2009 of the Chaitén dome complex (courtesy Mr Javier Romero, Vialidad MOP, Puerto Montt).

During the coming week, to mark the second anniversary of Chaitén’s awakening, there’ll be a series of posts here at the Volcanism Blog looking at various aspects – volcanological, social, economic and environmental – of this remarkable and endlessly fascinating eruption.

Secuencia de imagenes del volcan Chaiten correspondientes al mes de Marzo del 2010 (SERNAGEOMIN)
Sequence of images of the Chaitén lava dome during March 2010 (SERNAGEOMIN).

[The first illustration above, showing Chaitén before the eruption, was originally published here in May 2008; the second is from SERNAGEOMIN bulletin no. 91, translated here in May 2009; and the third is from the March 2010 bulletin (PDF) issued by SERNAGEOMIN which we will be reporting here very shortly.]

UPDATE. Family problems of a serious nature mean I’ve been unable to provide the Chaitén coverage promised in this post – please accept my sincere apologies. I will catch up with Chaitén, and with much else, when I am able to do so.

For all our Chaitén coverage: Chaitén « The Volcanism Blog.

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Keeping up with Chaitén via the DGAC and OVDAS webcams 2 May 2010

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For the last two years we have been watching the Chaitén volcanic eruption through the cameras operated by the Chilean civil aviation authority, the Dirección General de Aeronáutica Civil de Chile (DGAC), at Chaitén airfield. The DGAC deserves congratulations for keeping those cameras working night and day, through the sometimes very difficult conditions thrown up by the weather and the volcano.

The DGAC does not deserve any congratulations, however, for redesigning their website without a thought for their visitors and rendering all former URLs invalid. There’s no attempt to forward you to the new page, or even to help you find it: ‘no es posible encontrar la página solicitada’, they say, as if it’s your fault for asking. The outcome is that all previous links to the Chaitén cameras on this blog and everywhere else are now broken. And it’s not as if the newly re-designed site is any better than its predecessor: it’s still script-heavy, ugly, and slow. Anyway, the new links are as follows:

  • Cámaras de Chile: List of DGAC airfield cameras (with a map to show you where they are)
  • Aeródromo Chaitén: page for the two Chaitén airfield cameras (showing the current images alongside an archive image for reference)
  • Chaitén Cámara Norte: Chaitén airfield north-facing camera, the one that shows the volcano (current image, and archived images for the previous three hours)
  • Chaitén Cámara S-Este: Chaitén airfield south-east-facing camera, the one that shows the river (current image, and archived images for the previous three hours)

As for one Chilean state agency site that could do with a radical redesign, that of the Observatorio Volcanológico de los Andes del Sur (OVDAS), it continues unaltered, a visual and organizational catastrophe and a potent demonstration of everything you shouldn’t do when designing a website. But at least the locations of the OVDAS Chaitén cameras are unchanged:

For all our Chaitén coverage: Chaitén « The Volcanism Blog.

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Llaima: increase in seismic activity leads to increased alert level 27 April 2010

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Chilean state geological service SERNAGEOMIN announced on 25 April that the alert level for Llaima is being raised from Yellow Level 3 to Yellow Level 4 because of ‘the occurrence of earthquakes with high energy levels and tremor signals with durations of up to 20 minutes’. OVDAS volcanologist Gustavo Fuentealba is quoted in El Mercurio as warning that the crater of Llaima remains obstructed (as confirmed in ONEMI’s bulletin of 25 April, which reports the findings of an overflight of the volcano), and that this ‘increases the risk of a new eruption’. There is no change in the appearance of the volcano; fumarolic activity continues from the summit crater.

[Thanks to regular reader Guillermo for information about Llaima.]

For all our Llaima coverage: Llaima « The Volcanism Blog.

News
Alarma por alerta amarilla en el volcán LlaimaLa Nación, 24 April 2010
En alerta amarilla cinco comunas adyacentes al volcán LlaimaEl Mercurio, 25 April 2010
Onemi decretó alerta amarilla por actividad en el volcán Llaima – Cooperativa.cl, 26 April 2010

Information
Global Volcanism Program: Llaima – summary information for Llaima (1507-11=)
Oficina Nacional de Emergencia – Chilean government emergencies office
SERNAGEOMIN – Servicio Nacional de Geología y Minería, Chile
Proyecto Observación Visual Volcán Llaima – Llaima Visual Observation Project

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NASA Earth Observatory: cool flows at Llullaillaco 29 March 2010

Posted by admin in Argentina, Chile, Llullaillaco, NASA Earth Observatory, volcanoes.
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Llullaillaco volcano, Argentina-Chile border (ISS astronaut photograph, 9 Dec 2009)

The latest image of the day at the NASA Earth Observatory is this astronaut photograph of Llullaillaco volcano, which is situated on the Argentina/Chile border. Llullaillaco is the highest historically active volcano in the world, 6739 metres high, and last erupted in the nineteenth century. The lava flow extending to the north of the volcano shows very clearly features typical of a viscous flow on a steep slope. Lava at the edges of the flow has cooled more rapidly than that in the centre to produce the walled channel effect of a flow levée, while the faster cooling of the upper surface of the lobe at the front of the flow has produced characteristic layering and pressure ridges at 90 degrees to the direction of the flow. The Earth Observatory caption refers to the lobes of this flow as coulées (but this is what I call a coulée).

It’s also interesting to note, given the time of year, that the head of the Easter Bunny is clearly visible between the two lobes of the lava flow in the top right of the image:

The Llullaillaco Easter Bunny

[Astronaut photograph ISS022-E-8285 was acquired on December 9, 2009, with a Nikon D2Xs digital camera using an 800mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 22 crew.]

Llullaillaco volcano, Argentina-Chile border – NASA Earth Observatory, 29 March 2010

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Lowered alert level at Llaima 27 March 2010

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The Chilean state geological service SERNAGEOMIN reports in its latest Llaima bulletin that during 5-22 March 2010 ‘seismic activity around Llaima volcano has in general declined, returning to the levels shown before the earthquake of 27 February’. An overflight on 10 March revealed a low level of fumarolic activity, with occasional small white emissions columns reaching approximately 100 metres above the main crater.

As a result of the low levels of activity, the alert level for Llaima (which was raised on 5 March) has been reduced to Yellow Level 3, but the 4-km radius exclusion zone around the crater is remaining in place, and the volcano will continue to be monitored on a continuous basis.

The full Llaima bulletin covering 5-22 March 2010 is available as a PDF here.

For all our Llaima coverage: Llaima « The Volcanism Blog.

Information
Global Volcanism Program: Llaima – summary information for Llaima (1507-11=)
Oficina Nacional de Emergencia – Chilean government emergencies office
SERNAGEOMIN – Servicio Nacional de Geología y Minería, Chile
Proyecto Observación Visual Volcán Llaima – Llaima Visual Observation Project

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Chile: rumbles under Melimoyu 22 March 2010

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Is another Chilean volcano awakening? Melimoyu volcano in the Aysén region of southern Chile, a glaciated stratovolcano with a summit elevation of 2400 m and a distinctive horned profile, has been making some seismic noise over the past few days. Chile’s state geological service SERNAGEOMIN reported on 20 March that three earthquakes, two of magnitude 3.3 and one of magnitude 5.0, were detected on 17 March beneath Melimoyu. The earthquakes, which have been felt by people in towns near the volcano, continued at a lower level on 18 March.

The earthquakes were detected by the University of Chile’s seismological network and by the network set up to monitor the eruption of Chaitén volcano, which is 140 km north of Melimoyu. The foci were located beneath Melimoyu, at depths of between 3 and 22 km. As of the publication of the SERNAGEOMIN bulletin on 20 March the seismic activity was continuing with magnitudes between 2.0 and 3.0 and frequencies of up to 2 earthquakes per hour; during the activity of 18 March the frequency had reached 8 earthquakes per hour. However, no visual anomalies have been detected at Melimoyu.

SERNAGEOMIN has responded to this activity with commendable speed by installing a network of six seismic stations at Melimoyu to enable permanent monitoring of the volcano.

Pilar Cuevas Mardones, Intendenta of Aysén region, is quoted in El Diario de Aysén as saying that the seismic activity at Melimoyu ‘may indicate the possible beginning of activity at the volcano, which has been dormant for many years’.

News
Alerta por Volcán MelimoyuEl Diario de Aysén, 22 March 2010

Information
Global Volcanism Program: Melimoyu – information from the GVP about Melimoyu ((1508-052)
SERNAGEOMIN – website of the Chilean state geological service

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