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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
 White Island - degassing and returning of the lake to the crater - DoC. GeoNet end of May

White Island - degassing and returning of the lake to the crater - DoC. GeoNet end of May

Although a short-lived wave of seismic activity occurred on June 1, volcanic activity at Whakaari / White Island remains at low levels. The volcanic alert level remains at 1.
A brief period of low energy volcanic tremor was recorded on June 1 around 4 a.m., lasting two hours.


Web camera observations since May 18 indicate that water has filled the vents at the 2019 primary crater and this was confirmed during an observation flight on May 27. A small lake now occupies the 2019 primary crater, and no ejected material is apparent on the crater. Several active steam and gas vents are now underwater. Thermal infrared measurements from observation flights also confirm that the temperatures of the active vents are cooling considerably.
Gas and observation flights confirmed that the amount of gas released by the volcano has not changed much in recent months. The volcano continues to produce a weak to moderate gas and vapor plume, which may cause weak acid rain downwind of the island as usual.
Overall, the seismic tremor level remains at background levels. These observations and the minor activity observed are consistent with the ongoing activity at Whakaari / White Island. The volcanic alert level remains at 1 and the aviation color code remains green.

 

Source: GeoNet 09,06,2021

Soufriere de St. Vincent - aerial view of the crater -, photo 06.2021 R. De Freitas. via UWI

Soufriere de St. Vincent - aerial view of the crater -, photo 06.2021 R. De Freitas. via UWI

Soufrière de St. Vincent - darinages where lahars were recorded between 05 and 07.06.2021 - Doc. UWI-SRC

Soufrière de St. Vincent - darinages where lahars were recorded between 05 and 07.06.2021 - Doc. UWI-SRC

With the start of the rainy season, the main danger at Soufrière de St Vincent remains the risk of lahars. The image below shows where lahars were recorded between June 5-7.

The UWI-RSC reminds you of the instructions to be followed in this case :

- Danger in drainages, where lahars, similar in consistency to liquid concrete can carry tree trunks and large rocks.

- It is also dangerous to walk on sediment deposited in drainages and flood zones.

- The population must remain high and safe until advised by the authorities.


 

Source: Uwi-RSC & CDEMA

Sabancaya - activity report from 05.31 to 06.06.2021 / IGPeru

Sabancaya - activity report from 05.31 to 06.06.2021 / IGPeru

During the first week of June in Peru, the Sabancaya maintained itself at moderate levels, with an average of 96 explosions per day, accompanied by plumes rising up to 4,000 meters above the summit.

I.G.P. At the same time recorded 716 volcanic earthquakes related to the circulation of internal magmatic fluids.

We do not notice any significant deformation. Six thermal anomalies, with a maximum value of 16 MW, are observed, associated with the presence of a surface lava body in the crater.

The alert level remains in Naranja, with a non-accessible area with a radius of 12 km


 

Source: I.G. Peru

Geldingadalur - event active on 06/09/2021 / 11:14 p.m. - mbls webcam

Geldingadalur - event active on 06/09/2021 / 11:14 p.m. - mbls webcam

" Little by little the crater is closing " Þorvaldur Þórðarson, a geologist at the Institute of Earth Sciences at the University of Iceland, told mbl.is, referring to the crater of the Fagradalsfjall eruption, in southwest Iceland.

Little by little lava accumulates. In addition, the lava spurts are added to the crater. He explains that most of the lava that flows from the crater flows under a lava crust, invisible on the surface.

The situation is evolving towards the formation of a shield volcano, which can only be confirmed when a large lava lake has formed in the crater.

What happens when such a lake forms is that there is a flow from below and a constant flow in different directions. The lake feeds the lava flow, and all around the crater, [solidified] lava accumulates. Then we start to get a shield shape. "


Otti Rafn Sigmarsson, who works for the Þorbjörn rescue team in Grindavík, says hikers can no longer get as close to the eruption as before. The rash is clearly visible, but not as impressive as before.

He notes that the forest fires near the edge of the lava stream have subsided.


 

Source: mbls

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