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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
La Palma / Cumbre Vieja - new lava entry at sea on 23.11.2021 - screenshot

La Palma / Cumbre Vieja - new lava entry at sea on 23.11.2021 - screenshot

La Palma / Cumbre Vieja - lava flows at 23.11.2021 - Copernicus / IGN / via DSN

La Palma / Cumbre Vieja - lava flows at 23.11.2021 - Copernicus / IGN / via DSN

In La Palma, the eruption of Cumbre Vieja continues.

Currently, several emission centers with variable activity and with a greater lava input are still active in the northern zone, which with its arrival at sea forms a new lava delta.

During the afternoon, a plume of brown ash, due to partial collapse of the wall, joined the plume of white gas and vapor caused by the entry of lava into the sea.

La Palma - seismicity at 23.11.2021 / 08:42 - Doc. IGN

La Palma - seismicity at 23.11.2021 / 08:42 - Doc. IGN

La Palma - RSAM at 24.11.2021 / 05h45 - Doc. IGN

La Palma - RSAM at 24.11.2021 / 05h45 - Doc. IGN

The level of seismicity has increased at depths greater than 20 km., While at intermediate depths it continues to be located in the same areas. IGN reports a total of 98 earthquakes, including 84 deep earthquakes, about 30 km away on 23 November at 09h UTC. The tremor remains permanently at a low level.

The total area affected by the volcanic eruption on the island of La Palma is already estimated at more than 1,073 ha, with a maximum width between the external flows of around 3,300 meters.

The weather conditions remain unfavorable for aeronautical operations, mainly for La Palma airport.

 

Sources: IGN, IGME, Pevolca, DSN, RTVC

White island - View of the activated ventilation zone 1811.2021 - photo GeoNet

White island - View of the activated ventilation zone 1811.2021 - photo GeoNet

In Whakaari / White Island, volcanic unrest continues with releases of steam and mud, decreased gas emissions, stable vent temperatures, stable around 240-260 ° C, and a drop in lake level .

Gas measurements have shown that volcanic gas emissions have decreased since the last measurements on November 2, 2021. Sulfur dioxide has fallen from 681 tonnes per day to 484 tonnes per day. Carbon dioxide emissions decreased from 2,712 to 1,416 tonnes per day, while those of hydrogen sulphide also decreased from 38 to 19 tonnes per day. These data are consistent with the fact that gas continues to be released from molten material (magma) deep beneath the volcano.

Very low ash emission occurred during observations last week; recent ash deposits on the island are minor and visible only near active vents.

The volcanic alert level remains at 2.
The aviation color code remains yellow.

 

Source: GeoNet - 23,11,2021 / 1pm

Etna - Map of summit craters as of 23.11.2021 - Doc. INGV

Etna - Map of summit craters as of 23.11.2021 - Doc. INGV

Etna - INGV webcam on 11.20.2021 10:18 am and on 11.21.2021 7.14 am - Emov webcam and INGV annotations - one click to enlargeEtna - INGV webcam on 11.20.2021 10:18 am and on 11.21.2021 7.14 am - Emov webcam and INGV annotations - one click to enlarge

Etna - INGV webcam on 11.20.2021 10:18 am and on 11.21.2021 7.14 am - Emov webcam and INGV annotations - one click to enlarge

Review of active volcanoes in Sicily and the Aeolians by the INGV


In view of the monitoring data, the INGV mainly highlights degassing activities at the level of the summit craters of Etna. Explosive activity was observed on November 20 from 10:16 UTC at the northeast crater with emissions of diluted ash, and quickly dispersed.
A weak seismic fracturing activity, and a moderate infrasound activity are recorded. The amplitude of the volcanic tremor remains on the medium-low level.
No significant soil deformations measured by GNSS and clinometric networks
The SO2 flow is placed at an average level.
The flow of CO2 emitted by soils recorded by the EtnaGAS network last week was at medium-high values.
The partial pressure of dissolved CO2 in water shows a slight increase even though it is at average levels.
Thermal activity in the summit area was at a low level.

Stromboli - On November 20, a drone overflight was carried out: Thermal and RGB A and B image of the areas of the North (N) and Center-South (CS) craters. Thermal and RGB (C and D) detail of the N crater area which also highlights the many fumaroles in the upper part of the Sciara del Fuoco (E).

Stromboli - On November 20, a drone overflight was carried out: Thermal and RGB A and B image of the areas of the North (N) and Center-South (CS) craters. Thermal and RGB (C and D) detail of the N crater area which also highlights the many fumaroles in the upper part of the Sciara del Fuoco (E).

At Stromboli, a normal explosive activity of the Strombolian type was observed with a spattering activity culminating in a modest rheomorphic flow coming from the North zone. The total hourly frequency of explosions fluctuated between medium and high values ​​(14-25 events / h). The intensity of the explosions ranged from low to high in the North crater area and low to medium up to the Center-South crater area.

SO2 flux at an average level
The values ​​of CO2 flux recorded at Pizzo Sopra La Fossa are at high levels.

The thermal activity in the summit area is at a low level.

Vulcano - SO2 flux in tonnes per day from 18.09 to 31.11.2021 - Doc. INGV

Vulcano - SO2 flux in tonnes per day from 18.09 to 31.11.2021 - Doc. INGV

Vulcano - fumaroles from La Fossa on 23.11.2021 / 3 p.m. - Doc. INGV

Vulcano - fumaroles from La Fossa on 23.11.2021 / 3 p.m. - Doc. INGV

In Vulcano, the temperature values ​​are stable both on the edge and on the internal face of the crater of La Fossa, in line with those of the previous week at an average value of 319 ° C.

The CO2 values ​​in the crater area are increasing to very high and abnormal levels (13,743 g / m² / day)
The flow of SO2 in the crater area appears to be at a high level.

The CO2 flow measurements at the base of the cone acquired automatically by the VULCANOGAS network continue to display high values ​​and increase on the Camping Sicilia site.

Local seismicity continues to decline, with particular reference to low frequency events (VLP).

GNSS data shows, over the last week, a tendency to increase the expansion of the area, with a slight variation in the uptrend from November 20.
Only very localized and rapid gravity variations with a limited amplitude are recorded. There is no indication of significant deep mass redistributions.

 

Source: Weekly bulletins of Etna, Stromboli and vulccano posted on 23,11,2021

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