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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 : #Actualités volcaniques
 Piton de La Fournaise this 26th of october at 6h48 UT - Bert Piton webcam / OVPF

Piton de La Fournaise this 26th of october at 6h48 UT - Bert Piton webcam / OVPF

Since mid-October, a change is observed on the recordings of the volcanological observatory of Piton de La Fournaise with:


- a resumption of inflation (swelling) of the volcano: The GPS of the summit zone and in far field record an inflation, witness of the putting in pressure of a superficial and a deep source.
- low concentrations of SO(coupled with CO2) and H2S (coupled with H2O vapor) observed in the summit emissions of Piton de la Fournaise.
- a slight seismicity under the summit craters. On 24.10, 3 volcano-tectonic earthquakes (VT) are recorded under the summit cone, including a magnitude of 0.27 with a duration of 3.72 sec.

All these parameters will be followed and confirmed in the coming days.

Source: OVPF
 

  Piton de La Fournaise - Illustration of the summit deformation over 2 months. Here is shown a baseline (variation of distance between two GPS receivers) crossing the crater Dolomieu. A rise 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 summit deformation over 2 months. Here is shown a baseline (variation of distance between two GPS receivers) crossing the crater Dolomieu. A rise 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

At Agung, October 26, the status remains unchanged. A plume of steam is observed between 100 and 300 meters above the summit.
On 25 October, a non-harmonic tremor episode, 119 VA deep volcanic earthquakes, 87 VB superficial volcanic earthquakes, and two local tectonic earthquakes were recorded.

Agung - histogram of seismicity on 25.10.2017 - Doc. Magma Indonesia

Agung - histogram of seismicity on 25.10.2017 - Doc. Magma Indonesia

Agung scrutinized by volcanologists - local press photo

Agung scrutinized by volcanologists - local press photo

Despite a decreasing seismicity, volcanologist Devy Syahbana at the Rendang observatory recalls, in an interview with "Ubud now and then", that this is not the only factor to consider when setting the alert level.

The inflation marking the volcano is more than 6 cm, and the level of magma, raised to 4 km, is estimated at 18.5 million cubic meters. These factors somewhat offset the pressure from the local authorities to lower the alert level and allow operations to return to normal.


Sources: PVMBG, Magma Indonesia, Ubud now and then.

Ambae - the active cone in Lake Voui - photo Brad Scott October 2017

Ambae - the active cone in Lake Voui - photo Brad Scott October 2017

Almost a month after the total evacuation of the island following the eruption of Lombenben, the first inhabitants returned by boat to Ambae.
The operations are under control, at the beginning and at the finish, of the officials sent first. Food is sent at the same time for the refugees.
Some residents still fear a possible cataclysm, and at least one whole village has decided to get land on a nearby island.
Despite the lowering of the alert level, the government estimates that it is necessary to remain more than 3 km from the active vent in Lake Manaro Voui.
 
Sources: NPR, & Government of Vanuatu

 Ambae - return to the port of Lolopuepue - photo Gov.of Vanuatu 24.10.2017

 Ambae - return to the port of Lolopuepue - photo Gov.of Vanuatu 24.10.2017

Commenter cet article

Adrià Miró 26/10/2017 21:20

Thank's Bernard Duyck for your work every day! I read you 365 days from Catalonia. :)

Bernard Duyck 27/10/2017 11:55

Gracias por ser y permanecer un lector fiel

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