SERNAGEOMIN have issued their Bulletin No. 49 on the Chaitén eruption, dated 19 August, which can be found (as a PDF) at Werner Luis’s Chaitén site. The document runs to three pages and includes a number of illustrative figures. The overall picture is one of a steady-state low-level eruption with variable but basically low seismicity. The changes in seismic behaviour at Chaitén over recent days do not appear to correlate with any changes in the volcano’s eruptive behaviour: increases in seismicity did not relate to increases in eruptive activity, and recent decreases have not corresponded to declines in activity. SERNAGEOMIN are keeping a close watch on developments are are maintaining Volcanic Red Alert, as before.

To read the whole document in translation, complete with figures, click on ‘more’.

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Chaitén may not be doing anything particularly dramatic at the moment, but it is still erupting, as it has been continuously for more than three months, and the effects of its activity on the region remain profound. Even if the volcano is no longer on the front pages (even in Chile itself), it is important not to forget about Chaitén. One English-language insight into the effects the eruption has had and is still having on local communities is provided by the Chile Forum at allchile.net, which has a lively thread on Chaitén which started at the same time the eruption and is still going strong. Click here to visit the discussion.

For all our Chaitén coverage: Chaitén « The Volcanism Blog

The most recent SERNAGEOMIN bulletin on Llaima (12 August 2008) noted that the volcano was showing activity similar to that of previous days. The pyroclastic cone within the main crater, which has been the seat of recent eruptions, was producing ‘an intense and continuous emission of steam, with small quantities of volcanic gases’; seismicity was reported to be at a low level. On 13 August weak ash emissions and nocturnal incandescence were reported by the POVI Llaima observation project.

Today from POVI comes news that Llaima is erupting once again with sporadic weak ash emissions that are being carried to the east by strong winds. The following picture comes from POVI and shows clearly the pulses of ash cloud produced by the activity within the main crater.

Many thanks to our friends at POVI for this information and the image, which is copyright POVI. Information about and pictures of all recent and current activity can be found of course at POVI’s Llaima site.

For all our Llaima coverage: Llaima « The Volcanism Blog

Information
Global Volcanism Program: Llaima - summary information for Llaima (1507-11=)
Volcán Llaima - information from the Observatorio Volcanológico de los Andes del Sur (Spanish)
Oficina Nacional de Emergencia - Chilean government emergencies office (Spanish)
SERNAGEOMIN - Servicio Nacional de Geología y Minería, Chile (Spanish)
Proyecto Observación Visual Volcán Llaima - Llaima Visual Observation Project

The latest SERNAGEOMIN technical report on the eruption of Chaitén, dated 13 August 2008, arrived by e-mail yesterday. The original document (PDF) can be found at Werner Luis’s comprehensive Chaitén site. The report came labelled ‘47th technical report’ but is headed ‘48th technical report’; frankly, I have lost count and don’t know which it should be, but that’s not terribly important. It is one of the longest and most detailed reports SERNAGEOMIN have issued and contains some interesting information about seismic activity at and around Chaitén between 2 and 13 August. It does not, however, offer any predictions as to the volcano’s future behaviour.

To access a full translation of this report (including all nine figures), click on ‘more’.

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The NASA Earth Observatory has published a rather striking image today showing the spread of the sulphur dioxide cloud released by Kasatochi since it began erupting on 8 August. The image, captured by the Ozone Monitoring Instrument on NASA’s Aura satellite on 12 August, shows the gas looping counter-clockwise across the Pacific Ocean and spreading across Canada and the United States.

The image as shown above has been cropped slightly to fit in here at The Volcanism Blog. To see the original image with an extended explanatory caption, click here. Take some time to explore the NASA Earth Observatory: it is a wonderful resource, for volcanoes and much more.

Information
Global Volcanism Program: Kasatochi - summary information for Kasatochi (1101-13-)
Alaska Volcano Observatory - AVO page on the Kasatochi eruption

The most recent SERNAGEOMIN bulletin on Chaitén was issued yesterday (dated 12 August 2008). It reports poor weather conditions preventing direct observation of the volcano, except on the morning of 8 August when ‘a continuous emission of gas and pyroclasts’ was observed ‘which generated an eruptive column of more than 1 kilometre in height that dispersed towards the east’. The picture above was taken from the town of Chaitén on 8 August and shows ‘the dome and the column of steam, gases and pyroclasts’.

An increase in the number and magnitude of volcanic-tectonic (VT) earthquakes was recorded over the preceding 24 hours, along with a ’sporadic appearance’ of hybrid (HB) and long period (LP) earthquakes and an increase in background tremor, ‘phenomena attributed principally to the ascent of magmatic fluids’. The bulletin ends by suggesting that the characteristics of this seismic behaviour can be interpreted as ‘indicators of internal activity within the system that, eventually, could manifest in increases in the eruptive activity of the volcano’.

The press in Chile and Argentina is reporting today that Chaitén volcano is showing signs of an increase in eruptive activity: the headlines suggest a possible ‘reactivation’ of the eruptive cycle. El Mercurio reports:

Although there were no explosions registered yesterday afternoon at Chaitén volcano, the massif showed an increase in its eruptive activity, which resulted in a greater expulsion of ash from its crater … In view of the erratic behaviour of the volcano, the volcanologists of Las Lagos Region are dealing with two possible scenarios: the end of the eruptive cycle or the beginning of an entirely new [eruptive cycle]. The latter case would be the more worrying as it cannot be ruled out that the massif - which began erupting on 2 May - will repeat the process with which it began and that the eruption will be prolonged for years in a cyclical manner.

A report in 123 Chile describes a column of ’smoke’ (humo) from Chaitén reaching six kilometres in altitude yesterday aftenoon: ‘during the night a rain of ashes was produced which fell on the abandoned city. The volcanic reactivation coincides with earthquakes of 2.2 on the Richter scale’. The Argentine newspaper Diario Los Andes also describes Chaitén volcano producing ‘a column of six kilometres in height, raining ash on the desolate town of the same name, and a series of earthquakes of medium intensity’.

UPDATE: The latest technical bulletin from SERNAGEOMIN has just arrived in my inbox (thanks, Javier). It’s a long and detailed document and I won’t be able to get around to translating and reporting on it until tomorrow, but it is worth noting that the ‘increased activity’ reported by the media (as instanced above) refers to 13 August and has not been continued. Today the activity has been at a lower level once again, similar to that of recent weeks.

For all our Chaitén coverage: Chaitén « The Volcanism Blog

News
Volcan Chaitén: Registran aumento de sismos y del temblor de fondo - infochubut.com, 13 August 2008 (Spanish)
Volcán Chaitén presentó reactivación de su proceso eruptivo - El Mercurio, 14 August 2008 (Spanish)
Se reactivo el Chaitén: columna de humo es de seis kilómetros - 123 Chile, 14 August 2008 (Spanish)
El Chaitén, nuevamente en erupción - Diario Los Andes, 14 August 2008 (Spanish)
Volcán Chaitén presentó reactivación proceso eruptivo - Ansalatina, 14 August 2008 (Spanish)
Increased activity at Chile’s Chaiten volcano - PR-Inside.com, 14 August 2008
Spike in activity at Chile’s Chaiten volcano - USA Today, 14 August 2008

Information
Global Volcanism Program: Chaitén - summary information for Chaitén (1508-41)
ONEMI, Oficina Nacional de Emergencia - Chilean government emergencies office (Spanish)
SERNAGEOMIN - Servicio Nacional de Geología y Minería (Spanish)
Erupción del Volcán Chaitén - extensive coverage of the Chaitén eruption

Three volcanoes are currently active in the Aleutian Islands: Okmok, Cleveland and Kasatochi. Chris Rowan at Highly Allocthonous ponders on this near-simultaneous eruption of three volcanoes in the same neighbourhood in an interesting post and asks. ‘Could the eruption of one have triggered the others?’ Answer: ‘no’. Disappointing news for volcanic chain-reaction catastrophists everywhere.

Kasatochi volcano in the Aleutian Islands erupted on 7 August: full information about this dramatic and powerful eruption can be found at the Alaska Volcano Observatory and via the coverage at Eruptions.

The images above come from the NASA Earth Observatory site (click on each image to go to the original Earth Observatory page for that image). The upper image, from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, shows Kasatochi’s brown eruption plume swirling counterclockwise from the volcano on 8 August 2008. The lower image comes from the Ozone Monitoring Instrument on NASA’s Aura satellite and indicates the levels of sulphur dioxide released by the Kasatochi eruption. The image was captured on 10 August 2008. The NASA caption for this image notes that the Kastachi eruption cloud contained about 1.5 million tons (1.36 million tonnes) of sulphur dioxide, and is one of the largest volcanic SO² clouds scientists have tracked since Chile’s Hudson volcano erupted in 1991.

Information
Global Volcanism Program: Kasatochi - summary information for Kasatochi (1101-13-)
Alaska Volcano Observatory - AVO page on the Kasatochi eruption

This natural-colour image of Kilauea releasing an eruption plume was captured on 7 August 2008 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite and is available on the NASA Earth Observatory site in both low-resolution and high-resolution versions. The grey eruption plume from the volcano can be seen blowing away to the south-west.

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

Information
Global Volcanism Program: Kilauea - summary information for Kilauea (1302-01-)
USGS Hawaiian Volcano Observatory - main page for the HVO
HVO Kilauea Status Page - the latest activity reports for Kilauea

The weather at Chaitén has been clear today, giving some excellent views of the volcano from the Chaitén airfield webcam. The following video (19 seconds long) is a compilation of webcam images from this morning, kindly contributed to The Volcanism Blog by Olaf Kossner.

Clicking on the image below will take you to a Photobucket page where you can view the video.

Many thanks to Olaf Kossner for providing this video.

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 - Servicio Nacional de Geología y Minería (Spanish)
Erupción del Volcán Chaitén - extensive coverage of the Chaitén eruption