August 04 , 2017. EN . Sinabung , Piton de la Fournaise , Sangay , Ticsani .

Home / blog georges Vitton / August 04 , 2017. EN . Sinabung , Piton de la Fournaise , Sangay , Ticsani .

August 04 , 2017. EN . Sinabung , Piton de la Fournaise , Sangay , Ticsani .

August 04 , 2017.

Sinabung , Indonesia :

G. Sinabung : Volcanic Activity Bulletin, 2 August 2017.

The volcano continued its eruption with a series of hot clouds on August 2, 2017. Since 20:09 this day it emitted a series of hot clouds of avalanches (pyroclastic flows). The height of the eruption columns reached 2000 to 3000 m above the summit, dissipating towards the south, and were followed by pyroclastic flows. A total of 16 pyroclastic flows until 23:10 are recorded. The sliding distance of the pyroclastic flows varies from 2500 to 4500 to the east, and have a duration of between 251 and 707 seconds. The ash column varies from 1000 to 4200 meters above the top of the volcano, sloping towards the south.

 

L’image contient peut-être : montagne

The impact of pyroclastic flows on the land still occurs in the zone prohibited by the Geological Agency – KESDM. The Geological Survey – KESDM reported that the status of G. Sinabung has been at level IV (AWAS) since 2 June 2015 with the recommendation that communities and visitors / tourists do not carry out activities within a radius of 3 km around the volcano, less than 7 km for the South-South-East sector, less than 6 km for the South-East sector and less than 4 km for the Northeast sector of G. Sinabung. People who live and settle near the rivers flowing from G. Sinabung must remain alert to the potential danger of the lahars. The volcanic activity of G. Sinabung in general up to the present day is characterized by low frequency earthquakes with more than 10 events per day and relatively low growth of the lava dome (~ 1 m3 / s) in volume based on the results of lava dome measurements obtained on 19 July 2017. This has reached 2.3 million M3.

L’image contient peut-être : montagne, nuage, ciel, plein air et nature
A pyroclastic flow starts under the lava dome of the Sinabung volcano on the island of Sumatra in Indonesia. Activity seems to be intensifying as at the beginning of 2014.

The head of the Geological Agency KESDM with the Regent of the District of Karo as well as the BPBDs agency Tanah Karo coordinates directly on the ground since May 24, 2017 and continuously follows the emergency intervention team of the Agency Sinabung – geological on the threat of eruption and pyroclastic flows in areas that have been banned, and lahars / floods / disasters for residents who live and move along, downstream and around the Laborus River.

Conclusion: G. Sinabung’s level of activity is still at level IV (AWAS).

L’image contient peut-être : nuage, ciel, montagne, plein air et nature

Pyroclastic flows are intensifying on the Sinabung volcano , island of Sumatra in Indonesia, as in the beginning of 2014.

Volcano Observatory Notice for Aviation (VONA):

Last Issued: 20170803/0531Z
Current Aviation Color Code: ORANGE

Volcanic Activity Summary:
Hot clouds avalanches with ash clouds at 00:54 UTC (07:54 local time). The Hot clouds avalanches lasted for 309 seconds.
Volcanic Cloud Height: Ash-cloud not visible.

Other Volcanic Cloud Information:
Ash cloud is moving to East – Southeast

Remarks:
Seismic activity is characterized by the Deep Volcanic Earthquake, Low Frequency Earthquake, and Hybrid Earthquake. Hot clouds is observed through the Southeast- East slope and reaches a distance of 2000 meters from the summit.

 

Source : VSI , Magma .

Photos : Olivier Grunewald ( www.oliviergrunewald.com ).

 

Piton de la Fournaise , La Réunion :

Activity report for Thursday, August 3, 2017 at 4:00 pm (local time).

The eruption begun on July 14 at 00:50 local time continues. The volcanic tremor (indicator of surface eruptive intensity) continues to decline very gradually (Figure 1).

 

Figure 1: Evolution of the RSAM (volcanic tremor and eruption intensity indicator) between 00:00 (20h UTC) on July 14th and 15h30 (11h30 UTC) on August 3rd on the seismic station of RVL, located on the flank South of the volcano. (© OVPF / IPGP)

In the field, no projection is visible. Most of the activity is now done in lava tunnels with some visible surface resurgences on low spatial extension.

– No earthquakes have been recorded in the past 24 hours.
– The trend recorded on deformation sensors, in particular GPS, at the top of the volcano, seems to register a resumption of inflation again. This parameter will be followed in the next few days.

 

L’image contient peut-être : nuage, ciel, plein air et nature

Estimates carried out using satellite methods via the HOTVOLC platform (OPGC – Clermont Ferrand) show a minimum flow rate of less than 1 m3 / s.

The total volume of lava emitted to date is estimated at 7.2 ± 2.4 Mm3 (MIROVA).

 

Source : OVPF

Photo : F. Leveneur

 

Sangay , Ecuador :

New eruption, of low intensity.

Summary :
The Sangay volcano, located in the province of Morona Santiago, 40 km north-west of the city of Macas, presents a new eruptive phase from 20 July 2017 after 8 months without major surface activity. Recent surface activity is characterized by low-energy ash emissions (up to 3 km altitude), the rolling of incandescent rocks, mainly on the East-South-East flank, a new flow of lava on this same flank. This low intensity activity is typical of the Sangay volcano and does not represent a threat to the outside of the volcanic cone. Based on the direction and wind speed, ash emissions could cause small ash falls to the west of the volcano, in inaccessible areas and possibly cross some of the country’s air routes.

Informe Especial Sangay N. 1 - 2017

Figure 1. Emission of ash on the Sangay, ~ 400 m above the level of the crater, directed towards the Southwest (source: ECU-911, 02/08/2017).

Direct Observations:
Over the last few weeks, visual observation conditions have varied, from days completely cloudy to clear days. Surface activity was characterized by low-energy gas and ash emissions at the crater, reaching heights of less than 500 m (Figure 1). In addition, at night it was possible to observe avalanches of incandescent blocks on the East-South-East flank descending more than one km below the crater (Figure 2).

Informe Especial Sangay N. 1 - 2017

Figure 2: Descent of incandescent material through the ESE flank of the volcano (source: ECU-911, 01/08/2017).

Observations by satellite.

Ash plumes:
According to the Washington VAAC, three clouds of ash have been observed since July 20, 2017 (two on 20/07 and one on 02/08) with altitudes between 2.3 and 3 km and directions between West and Northwest (Figure 3). Prior to this activity, the last clouds of ash detected by satellite date from November 17, 2016.

Informe Especial Sangay N. 1 - 2017

Figure 3. Sangay ash clouds between July 20 and August 2, 2017, ~ 2.3-3 km above crater level, directed westward (source: Washington VAAC).

Thermal alerts:
Infrared (thermal) sensors on various orbiting satellites around our country have detected the presence of numerous heat anomalies on the Sangay volcano during the last two days (Figure 4).

Informe Especial Sangay N. 1 - 2017

Figure 4: Temperature anomalies detected by the MODVOLC and FIRMS systems on Sangay volcano, 2 August 2017 (source: HGIP, Hawaii, FIRMS).

The FIRMS system detected 18 thermal anomalies on 2 August, which are clearly aligned on the East-South-East flank. The GOES-EAST satellite images observed a hot spot on the volcano since the night of 01/02, which continues today, confirming that the activity described continues.
In recent months, we have no seismic or acoustic recordings due to technical problems.

Interpretation:
After 8 months without surface activity, the Sangay volcano has a low intensity eruptive phase, similar to that observed in previous years.
Based on the direction and speed of the wind, ash emissions could cause minor ash falls to the west of the volcano and eventually cross some of the country’s air routes.
Thermal alerts and the observation of glowing blocks more than 1 km along the volcanic slopes indicate the possible descent of a lava flow on the East-South-East flank. This phenomenon is not a threat outside the volcanic cone.

The IGEPN is very aware of any changes in the conditions presented by the volcano.

Source : IGEPN

 

Ticsani , Peru :

1.- Sismo-volcanic monitoring:

VTP (Volcano – Tectonic Proximal) seismicity continues to dominate in the Ticsani volcano region. This characteristic has been persistent so far this year. VTP events observed within a radius of 6 km around the volcano crater showed a slight increase compared to the previous period (36 VTP / day) rising to 50 VTP per day.
Earthquakes of the VTD type (Volcano – Tectonic earthquakes) maintain low levels in their daily occurrence rate. During these weeks, 9 VTDs per day were observed. It is important to note that the day of the greatest occurrence of VTD-type earthquakes was on July 28 with 47 events, including the earthquake of 3.8 ML (local magnitude) recorded at 04:56 HL ( local hour) .
On the other hand, during this period, there were only 4 hybrid earthquakes associated with magma movements. These events had low energy levels.

 

2.- Location of events:
The calculation of hypocentric parameters is carried out for earthquakes related to rock fracturing. On this occasion, the spatial distribution of the seismicity shows 2 seismic groups: group A (proximal) is located near the Ticsani volcano with earthquakes reaching depths of up to 8 km with respect to the crater. Group B (distal) is located 13 km south-east of Ticsani, with a depth distribution of 19 km. The highest energy quake recorded during this period of analysis was a distal event of magnitude 3.8 ML recorded July 28 at 04:56 HL 17 km southeast of Ticsani volcano.

3.- Satellite monitoring:
SO2 Anomalies: The GSO-NASA satellite system « EOS Aura » (http://so2.gsfc.nasa.gov/) recorded low SO2 gas density values ​​during this period.
Thermal anomalies: The MIROVA system (www.mirovaweb.it) did not detect thermal anomalies on the Ticsani volcano (VPR = 0 Megawatts).

CONCLUSIONS:

Seismic activity in the Ticsani region remains low. The dominant activity is related to the earthquakes associated with rock fracturing.
VTP-type earthquakes show a slight increase compared to the previous period; On average there were 50 events per day. The analysis of the seismicity also indicates the appearance of 4 events of hybrid type.
The spatial distribution of seismicity shows two groups of earthquakes: proximal (A) and distal (B). The highest-powered earthquake reached a magnitude of 3.8 ML and was located 17 km south of the Ticsani volcano.

Any changes will be reported in a timely manner.

 

Source : IGP

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