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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

At Etna, the week of October 4 to 10, 2021 was marked by degassing at the summit craters.

Seismic fracturing activity remains low, as does the magnitude of the volcanic tremor, and infrasonic activity.

No significant variation in soil deformation.

SO2 flux at an average level
The flux of CO2 emitted by soils is at medium-high values.

In addition, on October 4, 2021, an inspection was carried out in the summit area and the data compared to crater observations that were made with drones equipped with visible and thermal cameras during the year.
The comparison between the two DEMs shows a deepening of the hemlines to the southwest and east of the SEC identified by the red ellipse in Figure 3.3 B. In addition, the details of the crater rim of the SEC are characterized by some thermal anomalies in correspondence with the fumaroles.

 

Source: INGV OE

Etna - (A and B) 3D models of the south-eastern crater of Etna dating from September 16, 2021 and October 4, 2021, respectively. - (C and D) RGB and thermal images of the edge of the SEC crater taken on October 4, 2021. - Doc . INGV OE - one click to enlarge

Etna - (A and B) 3D models of the south-eastern crater of Etna dating from September 16, 2021 and October 4, 2021, respectively. - (C and D) RGB and thermal images of the edge of the SEC crater taken on October 4, 2021. - Doc . INGV OE - one click to enlarge

In recent days, the seismicity has increased slightly under the Piton de la Fournaise.

It follows more than 4 months of inflation of the volcano, synonymous with magma recharge of the superficial magmatic reservoir.

This seismicity remains low and superficial for the moment, and is most certainly linked to a disturbance of the superficial hydrothermal system by the rise of deep heat.

52 earthquakes were recorded last month and the trend has been increasing since September 20, especially in recent days:

- Number of volcano-tectonic earthquakes (VT) of 11-10-2021: 12
Zone affected by VT: Summit cone

Larger magnitude volcano-tectonic earthquake of 11-10-2021: Duration: 6.08 s - Magnitude of duration: 0.70

- Number of volcano-tectonic earthquakes (VT) of 12-10-2021: 10
Zone affected by VT: Summit cone

Larger magnitude volcano-tectonic earthquake of 12-10-2021: Duration: 6.36 s - Magnitude of duration: 0.74

In addition, more CO2 is observed in the soil.

 

Source: OVPF

Piton de La Fournaise - the dolomieu crater in the Enclos Fouqué - photo IRT

Piton de La Fournaise - the dolomieu crater in the Enclos Fouqué - photo IRT

Piton de La Fournaise - Illustration of the deformation over 2 months. The baselines (variation in distance between two GPS receivers) crossing the Piton de la Fournaise building, at the top (top), the base of the terminal cone (in the middle) and in the far field (bottom) are shown here. ) (see location on the associated maps). An increase is synonymous with elongation and therefore swelling of the volcano; conversely, a decrease is synonymous with contraction and therefore deflation of the volcano. Any periods colored in light pink correspond to eruptions. - Doc. OVPF

Piton de La Fournaise - Illustration of the deformation over 2 months. The baselines (variation in distance between two GPS receivers) crossing the Piton de la Fournaise building, at the top (top), the base of the terminal cone (in the middle) and in the far field (bottom) are shown here. ) (see location on the associated maps). An increase is synonymous with elongation and therefore swelling of the volcano; conversely, a decrease is synonymous with contraction and therefore deflation of the volcano. Any periods colored in light pink correspond to eruptions. - Doc. OVPF

The DSN communicated the situation on October 13/8 a.m. in La Palma / Cumbre Vieja eruption:

Three flows exist today; the most northerly flow forced the preventive evacuation of 700-800 people yesterday.

The weather conditions favoring air quality, the confinement of 3,500 people was lifted. The Canary Islands airports are operational.

The height of the eruptive plume reaches 3,500 meters, and drifts west, then south and east.

The lava extension is 656 ha. (+86.4 ha in 43h) the number of destroyed houses reached 1,458 (+135).

Seismicity continues at a depth of between 4 and 35 km, and earthquakes of M 3.6 maximum.

The volcanic tremor signal increased, possibly indicating a higher gas content of the magma at the eruptive center.

 

Sources: IGNes, InVolcan, DSN, Copernicus, Gobierno de Canarias

La Palma -  seismicity at 13.10.2021 / 08:16 - Doc. IGNes

La Palma - seismicity at 13.10.2021 / 08:16 - Doc. IGNes

La Palma - new area to be evacuated following the advance of the north flow - Doc. Gobierno de Canarias

La Palma - new area to be evacuated following the advance of the north flow - Doc. Gobierno de Canarias

La Palma / Cumbre Vieja - the lava flows on 12.10.2021 - Doc. Copernicus EMSR

La Palma / Cumbre Vieja - the lava flows on 12.10.2021 - Doc. Copernicus EMSR

La Palma / Cumbre Vieja - the lava flows seen from the north on 11.10.2021 / 19h - photo Ilovetheworld.es

La Palma / Cumbre Vieja - the lava flows seen from the north on 11.10.2021 / 19h - photo Ilovetheworld.es

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