There’s an interesting pairing of topographic views at the NASA Earth Observatory right now: a comparison of Chaitén and Mount St Helens volcanoes. The images are derived from elevation data collected by the Advanced Spaceborne Emission and Reflective Radiometer (ASTER) on NASA’s Terra satellite. The data for Chaitén were collected on 1 April 2006, before the current eruption, and the data for Mount St Helens were collected on 31 May 2007.

The images are to a uniform scale. Perhaps the most immediately striking thing is how large a feature Chaitén is, with its 2.5×4km caldera: the Global Volcanism Program calls it ’small’, which in comparison to Santorini (12×7km), Crater Lake (8×10km), or a real monster like Toba (35×100km), is probably fair enough, but it’s still pretty sizeable. The crater left at Mount St Helens by the May 1980 eruption looks quite modest by comparison, but is nothing of the kind, of course. It was also formed in quite a different way, through a catastrophic explosion; the Chaitén caldera was formed by the volcano collapsing into its own emptied magma chamber. Except when viewed from above Chaitén is an inconspicuous part of the landscape being low in elevation, the rim reaching 1122m at its highest point. Mount St Helens, at 2549m, is more than twice its height. It’s interesting to ponder what kind and size of edifice Chaitén was before the eruption that brought about its collapse into a caldera, 10,000 or so years ago.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Information
Global Volcanism Program: Chaitén - summary information for Chaitén (1508-41)
Global Volcanism Program: Mount St Helens - summary information for Mount St Helens (1201-05-)
USGS Photo Glossary: caldera - definition, explanation and illustration of ‘caldera’ from the USGS
Global Volcanism Program: calderas - more about calderas from the GVP’s ‘Types and Processes Gallery’

An interesting satellite image of Chaitén volcano has been published at the NASA Earth Observatory Natural Hazards site. Taken on 26 May 2008 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, the image shows what the commentary calls ’several unusual features that likely result from the volcano’s activity’: the blue-green colour along the coastline and on inland bodies of water (perhaps floating pumice), opaque white emissions from the volcano that fill the valleys and leave mountain peaks clear, and a combination of airborne and ground-deposited ash to the east.

Above is the full NASA image, with the plume being blown northwards from Chaitén. It appears that the heavier ash-bearing portions of the eruption cloud are sinking into, and dissipating through, the valleys - in the central part of the image, it almost looks as if milk has been spilt into the fissures of the landscape. To the right, over Argentina, the still-airborne ash can be distinguished from the ash deposits on the ground by its greyer colouring. Below is a close-up, taken from the large version of the image, of Chaitén volcano and its immediate surroundings. The widened channels of the sediment-filled rivers and the volcanic deposits that are being flushed into the sea clearly be seen. The brown area in the centre is Chaitén town, now flooded and engulfed by mud.

NASA images courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC.

UPDATE: Alan Sullivan has an interesting commentary on the image here. Also, see Werner Luis’s comment below in which he suggests that the coloured patches of water are more likely to be the result of suspended ash particles rather than floating pumice.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Information
Global Volcanism Program: Chaitén - summary information for Chaitén (1508-41)
ONEMI, Oficina Nacional de Emergencia - Chilean government emergencies office (Spanish)
SERNAGEOMIN - volcanology information from the Servicio Nacional de Geología y Minería (Spanish)

Pictures of the current fissure eruption at Etna, taken over the past few days, have just been added to the already vast collection of Etna images and resources at Stromboli Online. The new pictures show spectacular views of the activity at the new fissure, and cover the period from 16 to 24 May.

16-24 May 2008: Fissure eruption in Valle de Bove

Information
Global Volcanism Program: Etna - summary information for Etna (0101-06=)
Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania - INGV-CT is the volcanological authority responsible for Etna; current activity reports are here

The following four aerial photographs of Chaitén volcano were supplied to The Volcanism Blog by Werner Keller of the Villarrica and Llaima Volcanoes Visual Observation Project (POVI) in Chile - to whom, as ever, many thanks. The pictures were taken by Eric Manríquez and show the caldera and lava dome as they were before the current eruption began on 2 May, looking (broadly) towards the northern rim of the caldera.

A comparison with the photograph and satellite images published in our earlier post ‘Image of the Chaitén lava dome’ may be instructive.

These pictures are © Eric Manríquez.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Information
Global Volcanism Program: Chaitén - summary information for Chaitén (1508-41)
ONEMI, Oficina Nacional de Emergencia - Chilean government emergencies office (Spanish)
SERNAGEOMIN - volcanology information from the Servicio Nacional de Geología y Minería (Spanish)

A new satellite image of Chaitén volcano in eruption has been published at the NASA Earth Observatory Natural Hazards web site. The image was captured by Moderate Resolution Imaging Spectroradiometer (MODIS) equipment aboard NASA’s Terra satellite on 12 May 2008.

Above: the plume from Chaitén can be seen in the bottom left, extending eastwards across Argentina. Heavy ashfall can be seen north of the plume as a grey stain on the brown landscape of Patagonia. The original image with NASA commentary can be found here.

NASA images courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

There is a superb collection of Chaitén satellite imagery at the MiGeo geology blog, which provides excellent coverage of all aspects of geology with a particular emphasis on natural hazards. The blog comes out of Peru, and is in Spanish.

The article gives access to more than thirty satellite images, which come from a wide range of sources (and are fully referenced and linked back to those original sources) and cover the whole period of the eruption from 2 May 2008 onwards.

The article is an invaluable resource for understanding the Chaitén eruption: Erupción del Volcán Chaitén, Chile.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Two new satellite images of Chaitén volcano in eruption have been published at the NASA Earth Observatory Natural Hazards web site. The images were captured by Moderate Resolution Imaging Spectroradiometer (MODIS) equipment aboard NASA’s Terra satellite on 8 May 2008 (upper image) and 10 May 2008 (lower image). Links to the original pages containing the images at the Earth Observatory site are given in the captions below.

Above: image of Chaitén eruption captured by NASA’s Terra satellite, 8 May 2008. The eruption plume flows north-east from the volcano, dissipating over southern Argentina. The original image with NASA commentary can be found here.

Above: image of Chaitén eruption captured by NASA’s Terra satellite, 10 May 2008. There’s a lot more east in the direction of the plume than in the previous image, two days earlier. Heavy ashfall can be seen on the ground across Argentina. The original image with NASA commentary can be found here.

NASA images courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

The ongoing Chaitén eruption has produced some stunning images, from both terrestrial photography and satellite imaging. Not many have been featured here at The Volcanism Blog, partly for copyright reasons and partly because the images are easily available elsewhere. Below are some sites that are doing a particularly good job of showcasing some of the dramatic pictures that have come out of the Chaitén eruption. Please respect copyright in any use you make of these images.

• Erupción del volcán Chaitén - a constantly updated collection of still images and links to videos.
• Fotos do volcão Chaitén no Chile - a large collection of photographs of the eruption and its effects.
• Reuters AlertNet pictures - a collection of Reuters news images from the Americas: use the filters to select ‘Chile’ and a recent time period (e.g. ‘Chile’ + ’last week’) to find the Chaitén eruption images.
• Chilean volcano erupts - picture gallery from U.S. newspaper The Boston Globe.
• Emol.com: Erupción del volcán Chaitén - large collection of photographs from Chilean newspaper El Mercurio.
• Gobierno Regional de Los Lagos - numerous photographs of Chaitén with an emphasis on evacuation and relief measures, from the website of the regional administration.

The following collections are all hosted at the Chilean site Mega Galerias, and constitute only a small sample of what is available there. To list all the Chaitén galleries, use the keyword search (not the search at the top of the page, but the one marked ‘Ingresa palabra clave’ further down) and enter ‘Chaitén’. Make sure the accent is over the ‘e’, or it won’t want to know.

• Tormenta eléctrica en erupción del volcán Chaitén - over 30 images of the Chaitén eruption interacting dramatically with an electrical storm
• La erupción del volcán Chaitén desde el espacio - over 40 views of Chaitén from space and from the air
• Fotos del volcán Chaitén en la prensa internacional - pictures taken from the international press
• Chaitén bajo el volcán: Imágenes de este martes - pictures from the town of Chaitén, taken on Tuesday 6 May 2008
• El volcán Chaitén: Nuevas imágenes - a gallery of (currently more than 70) of the most recent Chaitén images

The Argentine weather site Nuestroclima, which is a great place to go for weather- and climate-related imagery, has a couple of posts featuring Chaitén images with commentary on its blog and will doubtless feature more as time goes on:

• Relámpagos sobre el volcán Chaitén - lightning over Chaitén volcano, with other images of the eruption
• Imágenes satelitales: erupción del volcán Chaitén (Chile) - satellite images of Chaitén, and related pictures

I’ll add to this list as I become aware of other good sources for Chaitén images. If you find any resources that should be listed here, please let me know.

Two new satellite images of Chaitén volcano in eruption have been published at the NASA Earth Observatory Natural Hazards web site. Both images were captured by Moderate Resolution Imaging Spectroradiometer (MODIS) equipment on 6 May 2008, the first (upper) by NASA’s Terra satellite at 11:05 local time and the second (lower) by NASA’s Aqua satellite at 15:15 local time.

Above: image of Chaitén eruption captured by NASA’s Terra satellite, 11:05 on 6 May 2008. The white plume can be seen deflected north-east from the volcano, then spreading eastwards across Argentina. Grey ash deposits mark the landscape south of the plume.

Above: image of Chaitén eruption captured by NASA’s Aqua satellite, 15:15 on 6 May 2008. Since the first image was taken a few hours earlier the plume has crossed the whole width of Argentina and has reached the Atlantic Ocean over Golfo San Matías, about 800km south of Buenos Aires. Large areas of ashfall are visible on the landscape below.

Full-size images, commentary and links to further information from NASA: EO Natural Hazards: Chaiten volcano erupts.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Two new satellite images of Chaitén in eruption have been published at the NASA Earth Observatory Natural Hazards web site. The images were captured on 5 May 2008 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite and show the eruption plume from the volcano extending due east for 650 kilometres across Chile and Argentina, with a grey coating of ash visible on the landscape beneath.

Above: Chaitén volcano erupts - natural colour image (NASA).

Above: Chaitén volcano erupts - infrared image (NASA).

These images have also been published at SpaceRef.com. Credit from original source: NASA images courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC.

For all our Chaitén coverage: Chaitén << The Volcanism Blog