November 02 , 2017. EN. Kilauea , Stromboli , Cumbal , Reventador .

Home / blog georges Vitton / November 02 , 2017. EN. Kilauea , Stromboli , Cumbal , Reventador .

November 02 , 2017. EN. Kilauea , Stromboli , Cumbal , Reventador .

November 02 , 2017.

 

Kilauea , Hawai :

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary:
Kīlauea Volcano continues to erupt at its summit and from the Puʻu ʻŌʻō vent on its East Rift Zone. The episode 61g lava flow is still entering the ocean at Kamokuna and producing scattered surface flow activity. These flows pose no threat to nearby communities at this time. This morning, the height of the lava lake at Kīlauea’s summit was measured at 33 m (108 ft) below the rim of Overlook crater. There have been no significant changes in ground deformation or seismicity rates across the volcano.

Summit Observations:
No significant change in tilt was recorded by summit tiltmeters in the past day, and the lava lake level was similarly consistent. The height of the lava lake has varied less than a few meters (yards) in the past week. This morning, the lake level was 33 m (108 ft) below the rim of Overlook crater, a drop of 4 m (13 ft) in the past 24 hours. Sulfur dioxide gas emission rates continue to be high. Seismicity rates were at normal, background levels, with tremor fluctuations related to lava lake spattering.

Puʻu ʻŌʻō Observations:
In the past day, seismic activity has continued at normal, background rates. The tiltmeter on Puʻu ʻŌʻō cone recorded no significant changes in tilt during the past day. Webcams showed persistent glow from long-term sources within the crater and from a small lava pond on the west side of the crater overnight. The sulfur dioxide emission rates from the East Rift Zone vents have been steady over the past several months, and remain significantly lower than the summit emissions.

Lava Flow Observations:
Lava from the episode 61g flow continues to flow down the pali, onto the Kamokuna delta, and into the sea. Webcam views overnight showed active flows on the upper flow field and small breakouts on the coastal plain. The episode 61g flows do not pose a threat to nearby communities at this time. At the ocean entry, a small steam plume was visible yesterday most of the time.

Source : HVO

 

Stromboli , Italy :

Stromboli: Update of the volcanic activity of November 1st, 2017.

At 08:29:56 UTC on November 1, Stromboli produced an explosive sequence of a total duration of about 3 minutes, having similar characteristics to that which occurred on October 23 at 14:04 UTC. Analysis of surveillance camera images showed that the sequence began with a high intensity event from the Central-South crater area, followed by a few small explosions in the following minutes (Fig. 1).

 

Fig. 1 – Initial phases of the explosive sequence taken by the thermal cameras (SQT) and visible (SQV) placed at 400m.

The sequence generated the fall of abundant coarse pyroclastic materials on the Sciara del Fuoco and Pizzo sopra la Fossa, and a plume of dense ash quickly dispersed by the wind on the southern slope of the volcano.

With the analysis of the seismic plot, it has been possible to specify that it is a typical explosive sequence – well known in volcanic literature – characterized by a series of transient phenomena, followed by a persistent signal (tremor) of a duration of a few minutes. This phenomenon is not necessarily linked to the rise of new magma.

 

No other significant phenomena occurred after this sequence. The seismic parameters also returned to the situation before the event.
Over the next few days, an inspection will be conducted to characterize the event in more detail. At present, it can not be ruled out that such events can be repeated in the short term.

Source : INGV

 

Cumbal , Colombia :

Subject: Cumbal Volcano Activity Bulletin.
The level of activity of the volcano is maintained at the level:
LEVEL YELLOW (III): CHANGES IN THE BEHAVIOR OF THE VOLCANIC ACTIVITY.

Following the activity of the CUMBAL VOLCANIC COMPLEX, the COLOMBIAN GEOLOGICAL SERVICE informs that:
For the week of October 24 to 30, 2017, seismic activity increased slightly compared to reported levels in the previous period, with a predominance of events associated with the movement of fluids from a transient source over time with low energy levels. Earthquakes associated with rock fracturing were found scattered beneath the volcano, with minor local amplitudes of M0.7 on the Richter scale and less than 8.5 km deep, related to the 4700 m altitude of the top of the volcanic complex).

 


Favorable climatic conditions at the summit allowed gas emissions to be recorded for all days of the week, mainly in the El Verde fumarolic fields in the north-east and Rastrojos in the south-west of the volcanic building.
The emission columns were observed of white color, of variable height and with directions of dispersion changing by the action of the wind.
The COLOMBIAN GEOLOGICAL SERVICE is attentive to the evolution of the volcanic phenomenon and will continue to inform in a timely manner about the detected changes.

Source : SGC

 

Reventador , Ecuador :

Update on the activity of the volcano
Abstract:

During the last week, the volcano showed a slight change in the intensity of its explosions, but not in the type of activity that has been presented since the increase since June 22. The columns associated with the emission and explosion signals are higher (> 2500 m) and have a high ash content. Sometimes they are accompanied by a violent gunshot, clearly heard in the surrounding cities. This type of explosion occurs every 4 to 5 hours. During the last 48 hours, ash falls have been reported in some towns south of the volcano, however, this phenomenon is more related to a change in wind direction than to a more significant change in the activity of the volcano.

Context
The last episode of increased eruptive activity began on June 22 this year, with continued activity generating pyroclastic flows and lava flows down the NE flank. During the month of August, the volcano showed a similar but less intense activity producing new lava flows towards the south and south-east flanks (IG-EPN, special report Reventador N. 4 – 2017). The explosions were frequent, about 35 to 40 explosions a day, and their emission columns were barely 1,500 meters above the crater level.

 

Visual observations and surface activity
A team from the Volcanology Department of the Institute of Geophysics conducted an observation mission between 23 and 25 October. During these dates, the explosions were large, with strong guns that produced vibrations of the ground and large windows of the Hostería Reventador, located about 7.2 km from the volcano. 

On 23 October, ash columns averaged 2500 m heights and even a maximum height of 4900 m on 27 October (Figure 1). The columns, which are generated by discrete explosions, have a high ash content (Figure 2). The preferred wind directions in the area are typically west and sometimes north and south. In the last hours the direction of the wind has been towards the South, causing falls of ashes in the Province of Napo, in some cities like: El Chaco, Gonzalo Diaz of Pineda (El Bombón), San Luis, San Carlos and El Salado (Source: SGR CZ2 Franklin Cárdenas, President San Luis – Pablo Ayaguari).

Informe Especial Reventador N. 5 - 2017

Figure 1. Above: ash column heights, a significant change was recorded on October 23 with columns> 2500 m snc; Below: prevailing directions of winds, note the last direction of the winds towards the south, source VAAC, (M Encalada – IGEPN).

 

Informe Especial Reventador N. 5 - 2017

Figure 2. Photograph of the El Reventador volcano, with a column of ash reaching 2000 m snc and heading north-east (Photo: B Bernard – IGEPN, 25 Oct-2017).

Seismic activity and infrasound.
Several seismic events were recorded during these days, with an approximate rate of 35 explosions / day, 45 long period / day earthquakes, 8 emission tremors / day. The frequency of big explosions is 4 to 5 hours between each event. The largest explosion was recorded on October 24, 2017 at 16:53 (21:53 UTC) (Figure 3), generating vibration of the ground and windows in the perimeter near the base of the volcano. Other explosions of similar intensity were heard and observed by the technical team working on the volcano on the 24th, which can be graphically recorded (Figure 4).

Informe Especial Reventador N. 5 - 2017

Figure 3. The maximum sound amplitude for each explosion event is presented from 01-06-2017 to 10-30-2017. A significant number of explosions are observed at the beginning of September 2017, to return to the base level in mid-October, and then see the increase observed at the end of October.

 

Informe Especial Reventador N. 5 - 2017

Figure 4. Seismic-acoustic record of the El Reventador volcano, there are two explosions whose acoustic signal (image on the right) is quite important, one of them being the most important recorded for the volcano in 2017 (BASE: IGEPN , 24oct-2017).

Thermal monitoring.
Thermal monitoring data from 23 to 24 October show explosions with apparent maximum temperatures above 500 ° C (Figure 5). The lava flows of June and August are in a cooling state with temperatures between 100 and 150 ° C, the fronts of these lava flows usually collapse and without any obvious activity in the crater which can be seen as small, hot avalanches that descend to the base of the cone (Fig. 6).

 

Informe Especial Reventador N. 5 - 2017

Figure 5. Thermal image of the El Reventador volcano (Image: M Almeida – IGEPN, October 24, 2017).

The thermal anomalies detected by the satellite sensors last week are summarized below:

FIRMS: 21 thermal alerts
MIROVA: 3 moderate thermal alerts.

Informe Especial Reventador N. 5 - 2017

Figure 6. Photograph of El Reventador volcano, left: explosion, the incandescent material can be seen through two vents on the summit; On the right: observation of deposits caused by the collapse of the south-east lava front, note the absence of activity at the crater level (Photo: B Bernard – IGEPN, 24oct-2017).

Gas.
The activity of the El Reventador volcano has been highlighted by satellite images. SO2 emissions were recorded, the largest on October 18, 2017, where values of nearly 400 tonnes were reached (Figure 7). Over the last few days, satellites have continued to record emissions, albeit on a smaller scale.

 

Informe Especial Reventador N. 5 - 2017

Figure 7. OMPS satellite image of the El Reventador volcano for October 18, 2017.

conclusions.
The volcano has levels of activity considered high, both indoors and outdoors.
Ash falls have been reported mainly in the province of Napo and part of Sucumbíos, which are produced according to the direction of the wind. At the time of this report it is preferentially towards the south.
There is no major change in the type of activity of the volcano since June, however, the explosions are more energetic, but occur less frequently, up to 5 hours between explosions. Associated explosions can be heard in villages near the volcano.
If this type of activity is maintained, we can continue to record a moderate fall of ash in areas near the volcano and even in more distal areas such as Pifo, Cayambe, Tababela, Quito, etc., if the columns exceed 3000 m and that the wind takes them to the West.
The large accumulation of ash in the upper parts of the cone can allow the generation of lahars or mudslides in conjunction with the presence of rain, so it is necessary to be aware of these phenomena.

Source : IGEPN

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