Overblog
Editer l'article Suivre ce blog Administration + Créer mon blog

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
Etna - activity of the Voragine and lava flow towards the Bocca Nuova on 18.09.2019 -.Photos by volcanological guide Marco Tomasello, via Boris Behncke

Etna - activity of the Voragine and lava flow towards the Bocca Nuova on 18.09.2019 -.Photos by volcanological guide Marco Tomasello, via Boris Behncke

The eruptive activity of Etna has reached a new stage ...

In Voragine, Strombolian activity continues; the gradual accumulation of pyroclastic material around the mouth has contributed to the growth of the slag cone formed around the explosive mouth, which now occupies a large part of the crater floor itself. In particular, observations made by the vulcanological guides in the last few hours show that explosive activity has developed and an intracratic lava flow has formed. The lava flow, after the saddle which separates the craters Voragine and Bocca Nuova, has poured inside this last crater, into two arms.

 Etna - activity of the Voragine and casting towards the Bocca Nuova on 18.09.2019 -.Photos by volcanological guide Marco Tomasello, via Boris Behncke

 Etna - activity of the Voragine and casting towards the Bocca Nuova on 18.09.2019 -.Photos by volcanological guide Marco Tomasello, via Boris Behncke

Etna- activity in Voragine and Bocca Nuova 18.09.2019 / 16:46 UTC - photo Jos.Nasi / Butterfly Helicopters

Etna- activity in Voragine and Bocca Nuova 18.09.2019 / 16:46 UTC - photo Jos.Nasi / Butterfly Helicopters

A slight tendency to increase of the average magnitude of the volcanic tremor has been seen since September 13th. Since the afternoon of day 16, this parameter has slightly exceeded the threshold between the average level and the high level, without presenting any rapid rapid variations, and reached a maximum in the early hours of yesterday, 17 September. Subsequently, the average magnitude of the tremor has shown a slight downward trend, with high and medium-high values ​​to date.

Regarding the location of the source of the tremor, since the night of yesterday, it has not touched the crater of the Northeast, but is below the crater of Voragine, in the meantime depth 2800-2900 m altitude.

As far as infrasound activity is concerned, it is maintained at a sustained level and is produced by Voragine and to a lesser extent by Bocca Nuova.

The soil deformation monitoring networks (Gnss and clinometrique) do not show any significant changes in recent days.

 

Sources: INGVvulcani and Marco Tomasello, via Boris Behncke.

Since September 18 in the morning, the seismic activity of Pacaya is rising, as indicated by the RSAM around 8,000 units.

Pacaya - RSAM 18.09.2019 morning - Doc. INSIVUMEH


Associated explosive activity is also increasing, with material ejections 100 meters above the intracratal cone and fallout around the Mackenney cone.

The feeding of lava flows on the northwest flank moves it towards Cerro Chino; constant avalanches of incandescent blocks of metric size are observed.

This situation can evolve upwards and initiate a new eruptive phase in terms of days or months.

 

Sources: Insivumeh & Conred

Reventador - photo archives 18.03.2019 E. Gaunt, IGEPN

Reventador - photo archives 18.03.2019 E. Gaunt, IGEPN

In Ecuador, the Reventador has high internal and surface activity on 18 September.

The seismicity is marked by 37 LP earthquakes, 40 explosion earthquakes, 7 emission tremor episodes and 4 harmonic tremor episodes.

Emissions of gas, more or less charged with ashes, form plumes that reach up to 1,000 meters in height, dispersing to the north and west.

Nighttime glow is observed at the crater, as well as on the avalanches of incandescent blocks on the west flank about 400 meters.

Alert level remains in Naranja

 

Source: IGEPN

Karangetang - image Sentinel-2 L1C image bands 12,11,4 zoom of 16.09.2019 - one click to enlarge

Karangetang - image Sentinel-2 L1C image bands 12,11,4 zoom of 16.09.2019 - one click to enlarge

In Karangetang, north of Sulawesi, in activity level 3 / siaga since November 2018, the activity remains intense.

Hot spots mark the two craters, as well as the lava flow west of the south crater.

At the seismicity level, the PVMBG reports 89 eruption earthquakes, 9 blast episodes, 3 volcanic earthquakes, 4 distant earthquakes and a continuous tremor of amplitude between 5 and 12 mm.

The danger zone concerns the 2.5 km around craters N and S, 4 km north-west of crater II and 3 km west of the main crater.

 

Sources: PVMBG & Sentinel-2

Commenter cet article

Articles récents

Hébergé par Overblog