August 29 , 2017. EN.  Bogoslof , Sabancaya , Piton de la Fournaise , Poas , Turrialba , Fuego .

Home / Alaska / August 29 , 2017. EN.  Bogoslof , Sabancaya , Piton de la Fournaise , Poas , Turrialba , Fuego .

August 29 , 2017. EN.  Bogoslof , Sabancaya , Piton de la Fournaise , Poas , Turrialba , Fuego .

August 29 , 2017.

Bogoslof , Alaska :

AVO/USGS Volcanic Activity Notice.

Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Issued: Monday, August 28, 2017, 3:53 AM AKDT
Source: Alaska Volcano Observatory
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

Bogoslof Volcano (Alaska) August 26, 2017 with a vigorous steam column probably caused by the interaction of the new hot lava dome with sea water. Photo by Dave Withrow (NOAA), taken at 13:00 AKDT on August 26 Aboard a NOAA (N56RF) aircraft. They were 13 nautical miles from Bogoslof when the picture was taken with a 400 mm lens.
Volcanic Activity Summary:
An explosive eruption began at Bogoslof volcano at 11:23 UTC (03:23 AKDT) on August 28 and is ongoing. No ash cloud has been detected as of yet in satellite data, but volcanic ash emission likely occurred based on seismic and infrasound data. Signal strengths suggest that the cloud is likely above 20,000 ft asl. Winds are towards the east-southeast.
The Aviation Color Code remains at ORANGE and the Volcano Alert Level remains at WATCH. AVO is evaluating all data sources and will provide more information as it becomes available.

Recent Observations:
[Volcanic cloud height] None detected yet.
[Other volcanic cloud information] winds toward east-southeast
[Lava flow/dome] N/A
[Lava flow] N/A
Please see the NWS AAWU at for updated information on aviation warning messages.

Unrest continues at Bogoslof volcano. Three short-duration eruptive events occurred at Bogoslof over the past day. On August 27, at 23:08 UTC (15:08 AKDT) a brief explosive event lasting about 2 minutes occurred and produced a volcanic cloud that reached about 26,000 ft above sea level and drifted southeast. Another explosive eruption occurred at 11:23 UTC (03:23 AKDT) August 28 and lasted about 25 minutes. Satellite imagery showed only a very small eruption cloud drifting east-southeast. This volcanic cloud dissipated quickly. The third event of the past day occurred this morning at 19:17 UTC (11:17 AKDT) and produced a small volcanic cloud that reached as high as 25,000-30,000 feet above sea level before dissipating over the North Pacific Ocean. Since this event, seismicity and infrasound as detected on neighboring islands has been quiet and no lightning has been detected.


The satellite and aerial images of the Bogoslof volcano in Alaska show its evolution and its constant change.
On August 7, one of the longest explosive eruptions occurred since the beginning of the eruption that began in December 2016. For three hours, the eruptive cloud was maintained, increasing the size of the island and creating A lake in the crater below the sea level.
The remainder of the month, the activity continued with a few surges on 15 August, which allowed to see the lava domes of previous eruptions (1796, 1883 (Fire Island), 1992 and 1926-1928), and the new Cone which is formed by the accumulation of ash. During the overflight, it was also possible to verify that, as on other occasions, the crater was flooded again with the entry of water from the near sea.
Three days later, on August 18, a satellite image was taken showing the commencement of construction of a new dome. Between 20 and 21 August, the dome, located on the inner lake west of the 1992 dome, reached 160 meters in diameter.
The presence of a growing mound of lava announced the end of several past eruptions of Bogoslof. However, during some periods of eruption, the effusion of lava was followed by further explosions and destruction of the dome. If future explosions occur, it is possible that the resulting volcanic cloud will be more ash-rich than those that have occurred so far in the Bogoslof eruption in 2016-17.


Source : AVO , Avcan , O. Rodriguez

Sabancaya , Pérou :

An average of 46 explosions were recorded per day, maintaining the trend observed since the second week of August. The predominance of earthquakes associated with the movement of fluids (long period) and earthquakes associated with ash emissions (Tremor) is continuing. The earthquakes associated with the uplift of magma (Hybrids) remain moderate in number and energy.
The eruptive columns of gas and ash increased their height from the previous week, reaching a maximum value of 4200 m above the crater. The dispersal of these materials occurred in a radius of more than 50 km, mainly in the south-east and north-west direction. During this period, the GPS station located to the South-East of the volcano did not record significant changes related to a deformation.

The volcanic gas flow (SO2) recorded a maximum of 2368 tons / day on 26 August, considered a moderate value. 8 thermal anomalies were recorded according to the MIROVA system, with values ​​between 1 MW and 75 MW of irradiated volcanic energy (VRP).
In general, eruptive activity maintains moderate levels. This type of behavior can continue over the next few days.

Source : IGP

Piton de la Fournaise , La Réunion :


Activity bulletin of Monday, August 28, 2017 at 09:30 (Local time).

End of the eruptive phase in progress since July 14, 2017.
The volcanic tremor (indicator of surface eruptive intensity), registered since the beginning of the eruption, disappeared last night. As a result, the eruptive phase that began on July 14 at 00:50 local time ended Aug. 28, 2017 at 3:00 local time (23:00 UTC August 27).
Since the end of this eruptive phase, we observe a resumption of the activity observed usually outside eruptive phase.

No assumptions are made as to the future situation, taking into account the following observations:
– Five volcano-tectonic earthquakes have been recorded under the southeast region of the enclosure since the end of the eruptive phase.
– No distortion is no longer noticeable.
– CO2 concentrations in the soil at the heel remain high.

Under these conditions, the Prefect of La Reunion decided to move into the safeguarding phase of the specific device ORSEC * of the Volcano of the Piton de la Fournaise , from 17:00 on Monday, August 28, 2017.
Despite the end of activity from the geophysical point of view and the stopping of the feed (end of the tremor, vibration associated with the path of magma and the gases it contains), no hypothesis is excluded as to evolution of the situation, an eruption  remains likely in the days and hours ahead.
Consequently, the prohibition of access to the upper part of the Enclos and the placing of aircraft in the area of ​​the volcano shall remain in force until further notice.

Source : OVPF.


Poas , Turrialba , Costa Rica :


Activity report of the volcanoes Poás, Turrialba, 28 August 2017, updated at 12.30.

Volcano Poas:
The Poas continues with the persistent emission of a plume of water vapor, magmatic gases and fine aerosols (very fine particles of micrometric size less than 10 microns, known as PM10, PM2.5, PM1) . The inhabitants of the western sector of the volcano reported a moderate ash fall (upper parts of Sarchí de Grécia, Trojas de Sarchí) in the last 24 hours. Two of the fumaroles in the bottom of the crater (Boca A and Boca C) emit blue plumes at high temperatures (≥ 300 ° C) rich in sulfuric magmatic gas, while Boca B (low temperature sulfuric mouth) of abundant native sulfur (≤110 ° C).

The plume rises about 500 meters from the bottom of the crater and is scattered by winds near the surface mainly to the northwestern region of the volcano. An incandescence of moderate intensity continues to manifest in the Boca A (red mouth) overnight.
Seismic activity is low; composed of short time intervals with a very low amplitude volcanic tremor (T), low frequency (LP) volcanic earthquakes and very low energy. In the last 24 hours, only a small volcano-tectonic (VT) earthquake near the active crater was recorded.

Turrialba Volcano:
The Turrialba continues with persistent but passive emissions of water vapor, magmatic gases and fine aerosols into the environment. Emissions of small amounts of ash continue to occur sporadically and for short periods. Some citizens reported falling ashes in San Jose (Guadalupe, San Pedro de Montes de Oca). The plume rises about 500 m above the level of the crater.
The wind is dispersing the plume at low altitude near the surface in a predominantly north-westerly direction. An intense incandescence is always noted in the western crater. Intense smoke degassing produces a sound similar to the motor of a jet.

Seismic activity over the last 24 hours has been characterized by a discontinuous volcanic low energy signal, both in amplitude and duration. Low frequency volcanic (LP) earthquakes are frequently recorded with low to moderate amplitudes. Tectonic activity (VT earthquakes) is still absent.
The OVSICORI-UNA is vigilant on volcanic and seismic activity.

Source : Ovsicori

Fuego , Guatemala :

Due to the constant precipitation in the volcanic zone, moderate lahars are generated by the floods of the Pantaleón, Cenizas, El Jute and Lajas rivers.
In the Pantaleón River, fed by the Seca and Mineral ravines, the flood reaches about 35 meters in width and a height of 2.5 to 3 meters, this lahar descends by causing the products of the deposits of pyroclast fluxes of the recent eruption, Carrying abundant fine materials, volcanic sand, blocks of 2 and 3 meters in diameter, and trees. It is likely that in its passage there will be overflows, in addition to cutting off the highway between the communities of Morelia, Santa Sofia, El Porvenir and others with the municipality of Yepocapa.

In the Cenizas river, the lahar is about 25 meters wide and 3 meters tall, and carries thin, medium and thick materials with blocks up to 2 meters in diameter. In the bed of the El Jute and Las Lajas rivers, it is estimated that the dimensions are about 20 meters wide, 1.5 meters high, with 1 to 2 meter diameter carved blocks, trunks and branches Trees. Caution should therefore be exercised, especially in vehicles crossing the ravines mentioned.

Source : Insivumeh .

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