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Tungurahua shows signs of awakening 8 January 2010

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For Tungurahua volcano in Ecuador, one of the most active volcanoes in South America, 2009 was a relatively quiet year of rumbles and roars, occasional crater incandescence, and periodic plumes and ashfall. The new year of 2010, however, has brought clear signs of an awakening of Mama Tungurahua.

A gradually declining trend in activity was evident at Tungurahua from the summer of 2009 onwards, but that has now clearly come to an end. The Instituto Geofísico of Ecuador published a special bulletin on 7 January 2010 (PDF) reporting that this trend reversed in mid-late December, and that there has been a marked increase in activity since 30 December 2009:

30 December 2009 – long-period earthquake followed by fumarolic activity with a steam plume reaching 300 metres above the crater.

1 January 2010 – beginning of emissions with low ash content, accompanied by rumbles that have gradually increased their intensity.

3 January 2010 – crater glow visible, lava fountaining begins, with the projection of incandescent material onto the upper slopes and intense rumbling sounds

4 January 2010 – increased ash emissions with eruption columns reaching as high as 2 km above the crater, ashfall reported to the west.

The bulletin also reports that seismic activity has continually increased since 31 December 2009, with numerous periods of tremor accompanying ash emissions, and sulphur dioxide emissions have also increased to 3,200 tonnes/day on 6 January 2010, ‘ten times the values recorded during the preceding weeks and months’. Overall, the Instituto Geofísico warns of further increases in activity, including increased ash emissions, over the next few days:

It is evident that the volcano has begun a new cycle of activity; the changes experienced have been shown in a rapid way, different to that seen on previous occasions when to generate the seismic activity that has been shown in the last 24 hours the volcano had to ‘work’ for weeks and months. In any case the activity occurring both at the surface and internally is considered to be at moderate levels but with clear signs that it is increasing.

Volcanologists have warned that substantial ash emissions, on a scale similar to those of summer 2006, cannot be ruled out. Heavy ashfall would have a damaging impact on agriculture, and local farmers and civic leaders are worried. Local communities are making preparations to deal with increased activity from Tungurahua, with efforts being made to stock up on face-masks and medical supplies and to prepare emergency shelters in the provinces of Tungurahua and Chimborazo.

News
Las emisiones de ceniza y gases aumentan en el TungurahuaEl Comercio, 5 January 2010
Rápido incremento de actividad de volcán TungurahuaEl Universo, 7 January 2010
El cantón Penipe en alerta por el volcán TungurahuaDiario Los Andes, 7 January 2010
Autoridades alerta con el despertar del TungurahuaLa Hora, 7 January 2010

Information
Global Volcanism Program: Tungurahua – summary information for Tungurahua (1502-80=)
Instituto Geofísico (Escuela Politecnica Nacional) – Geophysical Institute of Ecuador

The Volcanism Blog

Five new volcanoes discovered in Ecuador 18 December 2009

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The South American republic of Ecuador, spanning the northern Andes, is not exactly short of volcanoes: more than 50 Ecuadorian volcanoes are known, while the Global Volcanism Program lists 20 volcanoes with Holocene activity, including such great names as Cayambe, Reventador, Cotopaxi, Chimborazo and Tungurahua.

Well, there are going to be some additions to the list with the news that no fewer than five previously unknown volcanoes have just been discovered in north-central Ecuador by volcanologists Patricia Mothes and Minard Hall.

The newly identified ‘Cosanga Volcanoes’ are located in the Cordillera Real between Baez and Cosanga, about 75 km south-east of the Ecuadorian capital, Quito, and have been named Lavas de Bermejo, El Dorado, Domos de Huevo de Chivo, Centro Pumayacu and Centro Cosanga. Of these five Mothes and Hall report that at least one, Pumayacu, is potentially active – more work is needed before the potential activity level of the other four can be determined. The Cosanga volcanoes are relatively low features, between 2,800 and 3,700 metres, and are also relatively young, having formed between 2,000 and 20,000 years before the present. Around Pumayacu pottery fragments of the Cosanga culture have been excavated, which Hall suggests indicates that inhabitants of the area around 2,000 years ago may have had to leave because of volcanic eruptions at that time.

The identification of these unknown volcanoes was sparked by the discovery of obsidian in the Cosanga region. Further studies are planned, and Mothes and Hall do not rule out discovering yet more hidden Ecuadorian volcanoes.

[Thanks go to Volcanism Blog commenter Guillermo.]

News
Descubren cinco nuevos volcanes en Ecuador – BBC Mundo, 18 December 2009
Descubren 5 nuevos volcanes en Ecuador – Ecuador Ciencia, 13 December 2009
Descubren cinco nuevos volcanes en Ecuador – AFP, 13 December 2009

Information
Global Volcanism Program: volcanoes of Ecuador – Holocene volcanoes in Ecuador
Ecuador volcanoes and volcanics – information from the USGS Cascades Volcano Observatory

The Volcanism Blog

Llaima update, 8 December 2009 8 December 2009

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In Chile the state emergencies office ONEMI has issued a new bulletin on the situation at Llaima volcano, which has been on Yellow Alert since 5 December, reporting observations made by OVDAS-SERNAGEOMIN.

Seismicity at Llaima remains unstable ‘with events associated with fluid movements and processes of degasification’, and that numerous fumaroles have been visible when the weather has permitted direct observation.

Low concentrations of sulphur dioxide measured on 5 and 6 December indicate that the main crater remains obstructed. An overflight on 4 December also confirmed the blockage of the crater; fumarolic activity from fissures, mainly of white steam with some blue sulphur dioxide emissions, was observed on the north-east flank of the volcano and the interior north and exterior east and west walls of the crater. The largest fissure, and the seat of the greatest activity, was that situated on the north-east flank of the volcano which was the location of gas and ash emissions during April and June 2009.

Based on these observations ONEMI warns that new eruptive activity cannot be ruled out. Yellow Alert applies to Llaima and the districts of Melipeuco, Vilcún, Curacautín, Cunco and Lonquimay, and the 4-kilometre radius exclusion zone around the volcano remains in force.

The bulletin also announces that from today monitoring of Llaima is to be strengthened with several new broadband seismological stations, and three SERNAGEOMIN fieldwork teams are to be despatched to the area.

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

The Volcanism Blog

Alert level raised at Cerro Machín 7 December 2009

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Machin volcano, Colombia, 10 November 2008 (copyright INGEOMINAS)
Machín volcano, Colombia, 10 November 2008 (image copyright INGEOMINAS).

A seismic swarm on Saturday has provoked the Colombian state geological service INGEOMINAS to raise the alert level for Machín volcano in western central Colombia to Yellow (III), ‘ changes in the behaviour of the volcanic activity’.

According to a report in El Espectador, ’54 minor [earth] movements took place over the weekend at El Machín volcano. The largest of these was at 1.3 on the Richter scale. The seismic swarm took place from 5:00 p.m. on Saturday, and although small, is the largest to have occurred in 2009, after strong activity in 2008′. No bulletin on developments at Machín has yet been published on the Manizales Volcanological Observatory web site.

Any reactivation of Machín would pose a substantial threat to a populous area of Colombia, including the large city of Ibagué (approximate population 500,000).

UPDATE, 9 December 2009. A commenter at Erik Klemetti’s Eruptions blog observes that INGEOMINAS has had Machín at Yellow Alert for ages, and thinking back over my visits to the Observatorio Vulcanológico y Sismológico de Manizales site (where Machín bulletins are rather thin on the ground) it does seem that the yellow square has been a permanent fixture. I suspect the local press picked up on this activity because it’s the first for a while, and because the national government has prioritized a potential eruption of Machín as one of the principal natural disasters Colombia may have to deal with. In any case, the latest earthquake swarm is significant, and emphasizes the point that Machín needs careful monitoring.

News
54 sismos en volcán El Machín llevan a declarar alerta amarillaEl Espectador, 7 December 2009
En alerta Amarilla el volcán MachínSemana, 7 December 2009
Authorities declare yellow alert for Machin volcanoColombia Reports, 7 December 2009

Information
Global Volcanism Program: Machín – information about Machín volcano (1501-04=)
Observatorio Vulcanológico y Sismológico de Manizales – INGEOMINAS observatory responsible for monitoring Machín
Volcán Machín – information, maps and pictures

The Volcanism Blog

Llaima update, 7 December 2009 7 December 2009

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Some more information on activity at Llaima volcano in Chile, which is currently on Yellow Alert.

Chilean state emergencies office ONEMI has issued a new bulletin, reporting that ‘a seismic swarm associated with internal degasification’ and marked by ‘increased release of the volcano’s internal energy’ was detected at Llaima between 16:00 and 18:00 local time on 6 December. Fumarolic activity has been continuing, and the main crater remains obstructed. ONEMI is maintaining Yellow Alert for Llaima and surrounding communities, and the 4-kilometre radius exclusion zone remains in force.

Llaima volcano, 18 November 2009 (OVDAS-SERNAGEOMIN)
Above: Webcam image of Llaima volcano viewed from Cherquenco on 18 November 2009 (OVDAS-SERNAGEOMIN). [source]

The state geological service SERNAGEOMIN have also published a new Llaima bulletin on their web site today, which notes that fumarolic activity and volcanic gas emissions were observed during the period 14 November to 1 December when weather permitted, and contains the following information about recent changes in the volcano’s seismic activity:

Regarding the seismicity associated with Llaima volcano, it has been marked by the occurrence of a new type of LP [long period] event, of low frequency (less than 3.0 Hz), characterized by a spindle-shaped envelope with a higher amplitude (energy) than the other types of LP seismicity and a duration in some cases of up to 4 minutes. A continuing decline in the numbers of the other three types of LP earthquakes was observed, with an average 5 earthquakes per hour being registered, of which two to three correspond to this new type of event. The background tremor kept its characteristics of amplitude and spectral content.

The foregoing (the changes in the types of seismic events, which appear to be generated by different mechanisms) implies a greater complexity in the internal dynamics of the volcano. In addition, the main crater remains blocked, so the likelihood of a possible volcanic reactivation is greater than in previous months.

Yellow Alert, notes the bulletin, indicates that ‘eruptive activity may occur within weeks or months’.

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

The Volcanism Blog

Chile: yellow alert at restless Llaima 6 December 2009

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The Chilean state emergencies office ONEMI (Oficina Nacional de Emergencia) has declared a Yellow Alert for Llaima volcano and surrounding communities. According to an ONEMI bulletin issued yesterday, monitoring of the volcano by SERNAGEOMIN’s Observatorio Vulcanológico de los Andes del Sur (OVDAS) between 14 November and 1 December showed ‘continuing emission of water vapour, volcanic gases and background tremor’. This marks an increase in activity since mid-November – the appearance of background tremor is particularly significant. The bulletin reports that ‘considering the continuing obstruction of the main crater, and the appearance of these new types of seismic events, [OVDAS] indicates that these background conditions increase the likelihood of a possible eruptive reactivation of Llaima volcano, within the next few weeks’.

The Yellow Alert applies to the communities of Melipeuco, Cunco, Vilcún, Curacautín and Lonquimay: the authorities in these municipalities, along with those of the Conguillío National Park (within which Llaima is situated) are required to update and apply their emergency contingency plans and co-ordinate theire response with the local bureau of ONEMI. An exclusion zone of 4 km radius, centred on Llaima’s main crater, is in operation around the volcano itself.

In a further bulletin ONEMI clarifies that the effects of the increased alert level at Llaima are restricted to the enforcement of the exclusion zone around the volcano and more intensive monitoring of its activity, and that ‘the new Alert status does not create new restrictions on the normal activities of the population’.

UPDATE. The increased alert level ‘is a minor issue’ says the Intendenta of Araucanía Region, imposed by SERNAGEOMIN in response to a change in seismic behaviour: ‘this measure is not to alarm the community  but is an alert to the [monitoring] teams to remain vigilant’.

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

News
Declaran alerta amarilla por actividad del volcán en ChileEl Financiero, 5 December 2009
Chile decreta alerta amarilla en torno a volcán LlaimaEl Comercio, 5 December 2009
Alerta en Chile por posible erupción del volcán LlaimaLa Nación, 5 December 2009
Alerta amarilla por riesgo de erupción del volcán Llaima – Europa Press, 6 December 2009
Llaman a la calma ante aumento de actividad del volcán Llaima – 123 Chile, 6 December 2009

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

The Volcanism Blog

Galeras alert level reduced 28 November 2009

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The alert level for Galeras volcano in southern Colombia, which erupted on 20th November, has been reduced from level II Orange to level III Yellow, on a scale of I-IV, where I is the highest. The latest INGEOMINAS bulletin reports ‘continuing low levels of seismicity’ with an absence of the seismic signals which in the past have signalled the run-up to an eruption.

During the overflight of Galeras carried out on 26 November (which ended so tragically) gas emissions were observed from the edges, internal walls and areas of the floor of the principal crater, and thermal anomalies were detected with temperatures reaching 200° C.

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

Information
Global Volcanism Program – Galeras – summary information for Galeras (1501-08=)
Portal Corporativo de INGEOMINAS – Instituto Colombiano de Geología y Minería
Observatorio Vulcanológico y Sismológico de Pasto – Pasto volcanological observatory main page

The Volcanism Blog

Chaitén bulletins: no. 109 (30 October 2009) and no. 110 (13 November 2009) 24 November 2009

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In a remarkable development, SERNAGEOMIN has just released not one but two Chaitén bulletins to the public. Now available on the OVDAS ‘informes’ page are Chaitén bulletins 109 (PDF here, covering 16-30 October) and 110 (PDF here, covering 31 October to 13 November). Translations as follows.

CHAITÉN VOLCANO
TECHNICAL BULLETIN NO. 109
16-30 OCTOBER 2009
OVDAS-SERNAGEOMIN

1. Visual monitoring

During this period the volcano has remained obscured and only occasionally on 25 and 30 October has it been possible to observe the dome complex and its column of gas and ash. In general, the base of the column has appeared much wider, although the altitude has not exceeded 1.5 km above the domes (Fig. 1).

Chaiten 30 October 2009
Fig. 1. View from the DGAC camera in Chaitén on 30 October.

(more…)

Galeras update, 22 November 2009 22 November 2009

Posted by admin in activity reports, Colombia, eruptions, Galeras.
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Following yesterday’s eruption, the INGEOMINAS observatory at Pasto has lowered the alert level to the second-highest level of Orange, ‘eruption probable within days or weeks’. A bulletin released at 19:40 local time yesterday evening reporting the following:

Since the eruptive event of last night and following the notable increase in seismicity, the seismic activity has shown a gradual decline both in frequency and energy released. The earthquakes registered are associated principally with processes of [gas] escape although events related to the fracturing of crustal material have also been recorded. The seismicity occurs in the upper levels.

The measurements of sulphur dioxide (SO2) today show levels between low and moderate (with a maximum value of 700 tonnes/day), explicable in part to an opening of the system as a consequence of the eruption.

The eruptive event recorded yesterday reflects partial easing of forces and reduction of overpressures.

The bulletin concludes that ‘the volcanic process at Galeras remains unstable, with the presence of magmatic material in upper levels’, and warns that the volcano’s behaviour has shown that ‘in relatively short periods of time consecutive explosive events can be generated’.

Evacuation orders affecting around 7000-8000 local inhabitants were issued following the eruption yesterday. Local news sources reported that between 900 and 1000 people actually responded to the evacuation and went to the shelters.

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

News
Mil personas se encuentran en albergues por erupción del GalerasEl País, 21 November 2009
Volcán Galeras amanece en alerta Naranja ante eventual erupción – Caracol Radio, 22 November 2009
Sigue alerta roja por erupción del GalerasEl Tiempo, 22 November 2009

Information
Global Volcanism Program – Galeras – summary information for Galeras (1501-08=)
Portal Corporativo de INGEOMINAS – Instituto Colombiano de Geología y Minería
Observatorio Vulcanológico y Sismológico de Pasto – Pasto volcanological observatory main page

The Volcanism Blog

Catching up with Chaitén (and Llaima) 20 November 2009

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While we wait for SERNAGEOMIN to get around to publishing the latest Chaitén bulletins (which eventually appear as PDFs at the OVDAS site), two brief reports have appeared on the press page of SERNAGEOMIN’s main site, dated 9 November and 16 November, the latter economically combined with a report on Llaima. Translations as follows.

SERNAGEOMIN bulletin on Chaitén volcano
9 November 2009 [original here]

Between 16 and 30 October the eruptive activity of Chaitén volcano, both visually and seismically, has shown no large changes, continuing the developments of the last period. The preceding indicates that the eruptive activity continues with the growth of the dome complex.

On the other hand, the quantity of pyroclastic material both from rock falls and emitted by the block-and-ash flows and lateral explosions has created large accumulations in the adjacent valleys and particularly the valley of the Chaitén river, so that the occurrence of lahars towards Chaitén during periods of intense rain cannot be ruled out.

In consequence, given that the seismicity remains at elevated levels – an effect of the growth of the dome complex – and that the eruptive activity continues with the possibility of the generation of block-and-ash flows in random directions, which may affect surrounding valleys with the generation of new lahars, SERNAGEOMIN suggests maintaining Volcanic Red Alert.

Chaiten 30 October 2009
View from the DGAC camera in Chaitén on 30 October. In general, the base of the column appears much wider, although its height does not exceed 1.5 km above the domes.

SERNAGEOMIN bulletin on Chaitén and Llaima volcanoes
16 November 2009 [original here]

The images observed through the DGAC camera located in Chaitén to the south of the volcano show that during 31 October and 1 November the eruption has continued to produce one column, principally consisting of water vapour with occasional gas and ash. Because of the predominant winds in the area the height of the column has not exceeded 1000 metres above the dome complex. During the rest of the reporting period the continuing [cloud] cover has prevented any visual observation of the activity.

Chaiten 31 October 2009 (left), 1 November 2009 (right)
Images from the DGAC camera in Chaitén on 31 October (left) and 1 November (right).

Between 31 [October] and 1 November the seismicity has remained relatively stable compared with the preceding weeks indicating that the eruptive activity continues with the growth of the dome complex, only rarely observable recently because of the poor weather conditions in the area.

In consequence, given that the seismicity remains at elevated levels, an effect of the growth of the dome complex, and that the eruptive activity continues with the possibility of the generation of block-and-ash flows in random directions which may affect surrounding valleys with the generation of new lahars, SERNAGEOMIN suggests maintaining Volcanic Red Alert.

Llaima volcano

The poor meteorological conditions did not permitt visual observation of Llaima up to 10 November when it was possible to observe that the weak emissions of water vapour around the principal crater and on the east side of the volcano continue, probably due to the melting of snow deposited in these locations.

Although the seismic activity has shown a slight decline in the number of LP earthquakes, its general characteristics have shown the same behaviour as during the preceding period and apparently the principal crater remains obstructed. Given these conditions, it is not possible to rule out a reactivation of the volcano.

In consequence, SERNAGEOMIN maintains Alert Level Green 2 and continues with permanent monitoring of the volcano, and suggests keeping the 4 km radius of exclusion around the principal crater.

Additionally it is reiterated that this alert could change suddenly, depending on the activity observed/registered at the volcano, so that it is recommended that community preparations are maintained along with the revision and updating of emergency plans.

[End of SERNAGEOMIN bulletins.]

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

Information
Global Volcanism Program: Chaitén – summary information for Chaitén (1508-41)
Erupción del Volcán Chaitén – extensive coverage of the Chaitén eruption
Global Volcanism Program: Llaima – summary information for Llaima (1507-11=)
Proyecto Observación Visual Volcán Llaima – Llaima Visual Observation Project
SERNAGEOMIN – Servicio Nacional de Geología y Minería, Chile

The Volcanism Blog

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