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Earth of fire

Actualité volcanique, Articles de fond sur étude de volcan, tectonique, récits et photos de voyage

Publié le par Bernard Duyck
Publié dans : #volcanic activity
Sabancaya - I.G.Peru bulletin from 05.09 to 11.09.2022

Sabancaya - I.G.Peru bulletin from 05.09 to 11.09.2022

The eruptive activity of Sabancaya remained at moderate levels this week, with an average of 44 explosions per day, accompanied by plumes of gas and ash reaching 2,900 meters above the summit.

During this week, the IGP detected 347 earthquakes of volcanic origin associated with the circulation of internal magmatic fluids, as well as VT earthquakes related to rock fracturing. No significant deformation anomalies.

Ten thermal anomalies, from max. 28 MW, testify to the presence of a lava dome in the crater.

The volcanic alert remains at naranja, with a non-accessible zone of 12 km radius around the crater.

 

Source: I.G.Peru

Sabancaya - Radiative power as of 09.13.2022 / 03:30 - Doc. Mirova_MODIS_logVRP

Sabancaya - Radiative power as of 09.13.2022 / 03:30 - Doc. Mirova_MODIS_logVRP

An eruptive episode of Gunung Ibu occurred on Tuesday September 13, 2022 at 10:15 WIT with a thick white to gray ash plume, observed at ± 800 m above the peak (± 2125 m above sea level ). This eruption was recorded on a seismograph with a maximum amplitude of 28 mm and a duration of 70 seconds.

The level of activity remains at level 2 / waspada, with a recommendation for communities around Mount Ibu and visitors / tourists not to travel within a radius of 2.0 km and the sectoral expansion is 3.5 km towards the crater opening in the northern part of the active Mount Ibu crater.

 

Sources: PVMBG, Magma Indonesia

Gunung IBU - 2022.09.13 / 10:22 WIT - PVMBG Magma Indonesia webcam

Gunung IBU - 2022.09.13 / 10:22 WIT - PVMBG Magma Indonesia webcam

The OVDAS / Sernageomin communicates the activity of the volcanoes under its surveillance in August: all are on green level alert.

In particular for the Villarica:

Satellite geomorphological analysis:
From the photo interpretation of a high resolution image, Skysat type of August 22, 2022, the interior of the crater could be observed, identifying a subsidence of the lava lake with the formation of a crust in its upper part and the existence of a crack where the presence of molten material is observed, the crack has an ellipsoidal shape, with a major axis of 6.7 m and a minor axis of 3.5 m, covering an area of ​​19 m2. On the other hand, on the internal walls of the conduit where there is snow cover, deposits of ash-sized pyroclasts are observed, probably associated with a remobilization of material. No block-sized pyroclasts are identified either inside or outside the crater.

Villarica - a hot spot in the crater on 10.09.2022 - image Sentinel-2 Copernicus - one click to enlarge

Villarica - a hot spot in the crater on 10.09.2022 - image Sentinel-2 Copernicus - one click to enlarge

The seismological activity of the period was characterized by the recording of:
- 9 VT type seismic events, associated with rock fracturing (Volcano-Tectonics). The most energetic earthquake presented a local magnitude value (ML) equal to 1.2, located 4.8 km east-southeast of the volcanic edifice, at a depth of 3.0 km from the crater.
- 1449 LP-type seismic events, associated with fluid dynamics within the volcanic system (Long Period). The size of the largest earthquake estimated from the reduced displacement parameter (RD) was equal to 15 cm2
- 2 seismic events of the TR type, associated with sustained dynamics over time of the fluids inside the volcanic system (TRémor). The size of the largest earthquake estimated from the reduced displacement parameter (RD) was equal to 2 cm2

During the period, 8 thermal alerts were recorded in the area associated with the volcano, with a maximum Volcanic Radiative Power (VRP) of 2 MW on August 10, 19 and 28, a value considered low according to data processed by MIROVA. (http://www.mirovaweb.it/).

Through analysis of Sentinel 2L2A satellite images, 5 radiance anomalies were detected in the area associated with the crater on August 1, 3, 8, 21 and 29, with a maximum anomalous radiance area of ​​5400 m2 on August 28 .


The technical alert remains GREEN: Active volcano with stable behavior - There is no immediate risk, with a potential impact zone is considered within a radius of 300 m. from the rim of the active crater.

 

Source: Sernageomin / Villarica August 2022

La Palma / Cumbre Vieja - sismogram station TBT 12.09.2022 - Doc. IGN

La Palma / Cumbre Vieja - sismogram station TBT 12.09.2022 - Doc. IGN

Post-eruptive activity at Cumbre Vieja.

According to the Cabildo de La Palma, since December 13 the post-eruptive phase continues, in which some volcanic risks persist, without it being possible to exclude future reactivations. Seismicity related to the movement of volcanic fluids continues. There are no significant surface deformations of the ground related to magmatic activity. There is no presence of volcanic tremor in the seismic signals

The high temperatures and the instabilities of the terrain remain in the volcanic cone, as well as in the lava flows, "therefore persistent danger". Currently, an instrumental monitoring network is operational to continuously record CO2 (carbon dioxide) concentrations in ambient air, inside and outside buildings, in the population centers of Puerto Naos and La Bombilla, which currently integrates more than 20 sensors of different nature;

- The stations located in La Bombilla present a wide range of values, ranging from less than 5,000 ppm (parts per million) to values ​​greater than 200,000 ppm

- the daily average of the CO2 concentration in the outside ambient air recorded by the stations located in Puerto Naos "presents a wide range of values ​​ranging from less than 5,000 ppm to 10,000 ppm, with values ​​that exceed 45,000 ppm in some stations .

As a principle of precaution, prudence and prevention, it is advisable to keep the area , allowing access only for the exercise of the work activity, following the protocols established by the occupational risk services.

 

Sources: Cabildo de La Palma, via El Diario & IGN.es

Classification of outdoor CO2 levels (*) for the surroundings of Puerto Naos and La Bombilla, taking into account the current surveillance context existing in the area. These levels may be modified based on scientific evidence. (**) Vulnerable and sensitive population: pediatric population - Doc. Cabildo de La Palma 12.09.2022 / via El Diario

Classification of outdoor CO2 levels (*) for the surroundings of Puerto Naos and La Bombilla, taking into account the current surveillance context existing in the area. These levels may be modified based on scientific evidence. (**) Vulnerable and sensitive population: pediatric population - Doc. Cabildo de La Palma 12.09.2022 / via El Diario

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