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 - hot spots at the summit craters and other lava flows of the paroxysm of 08/29 - image Sentinel-2  bands 12,11,4 of 08/30/2021 - one click to enlarge

Etna - hot spots at the summit craters and other lava flows of the paroxysm of 08/29 - image Sentinel-2 bands 12,11,4 of 08/30/2021 - one click to enlarge

Etna - SO2 plume of paroxysm over the Greek islands on 08/30/2021 - Sentinel-5P image via Adam platform - one click to enlarge

Etna - SO2 plume of paroxysm over the Greek islands on 08/30/2021 - Sentinel-5P image via Adam platform - one click to enlarge

After the paroxysm of August 29, whose satellites show the extent of the field of lava flows and the extension of the sulfur dioxide plume following the eruption, a weak Strombolian activity resumed at the south-eastern crater of Etna on August 30 at around 8 p.m. UTC,
The trend of the mean amplitude of the volcanic tremor, from 20:00 UTC, is characterized by fluctuations on medium-low values. This activity ceased on August 31 at the end of the day.

The center of gravity of the volcanic tremor sources is located in the crater of Bocca Nuova at an altitude of about 2,700 m above sea level. Infrasonic activity is kept at low levels.

 

Source: INGV OE, Sentinel-5P and Sentinel-2

Etna - trémor on 01.09.2021 - Doc. INGV OE

Etna - trémor on 01.09.2021 - Doc. INGV OE

During the week of August 23-30, Sabancaya maintained moderate-level activity, with an average of 36 explosions per day, accompanied by ash and gas plumes reaching 3,500 m. above the summit.

I.G.P. recorded and analyzed 1,198 earthquakes of volcanic origin, associated with the circulation of magmatic fluids.

No significant deformation anomalies.

Mirova detected 10 thermal anomalies, with a max. of 27 MW VRP, associated with the presence of a surface lava body in the crater.

The alert level is maintained in Naranja, with an inaccessible area of 12 km in radius.

 

The activity continues.

 

Sources: I.G. Peru & Ingemmet

Sabancaya - summary of the activity from 23 to 30 August 2021 - photo I.G. Peru

Sabancaya - summary of the activity from 23 to 30 August 2021 - photo I.G. Peru

Sabancaya - explosions continue - 08.31.2021 / 11.57am - Cam. Ingemmet - OVI

Sabancaya - explosions continue - 08.31.2021 / 11.57am - Cam. Ingemmet - OVI

In August 2021, the OVPF recorded in the Piton de la Fournaise massif in total:
- 37 superficial volcano-tectonic earthquakes (0 to 2.5 km above sea level) under the summit craters
- 2 deep earthquakes (below sea level);
- 311 collapses (in the Crater Dolomieu, the ramparts of the Enclos Fouqué and Piton de Crac, and the Rivière de l'Est).

The inflation of the building, initiated in April 2021, continued throughout August 2021. This inflation showed a pressurization of the superficial magmatic reservoir located around 1.5-2 km deep .

Piton de La Fournaise - Illustration of the deformation over the last six months from March 1 to August 31, 2021 (eruptive periods are in red). The variations in distance between two GPS receivers crossing the Piton de la Fournaise building, at the top (BOMG reference; above), at the base of the terminal cone (FOAG reference; in the middle) and in the far field (reference PRAG; bottom). 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 (© OVPF-IPGP)

Piton de La Fournaise - Illustration of the deformation over the last six months from March 1 to August 31, 2021 (eruptive periods are in red). The variations in distance between two GPS receivers crossing the Piton de la Fournaise building, at the top (BOMG reference; above), at the base of the terminal cone (FOAG reference; in the middle) and in the far field (reference PRAG; bottom). 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 (© OVPF-IPGP)

The inflation of the building and the CO2 contents in the soil which remained high in August 2021, witnessed magmatic transfers from deep zones to the superficial magmatic reservoir which continued after the end of the eruption of April 9-May 24, 2021.

 

Source: OVPF - monthly bulletin

Soufriere of St. Vincent - the crater on 08/30/2021 - Doc. UWI-SRC - one click to enlarge

Soufriere of St. Vincent - the crater on 08/30/2021 - Doc. UWI-SRC - one click to enlarge

Seismic activity at La Soufrière in St. Vincent has remained low since the tremor associated with the explosion and ash removal on April 22. Over the past week, there has been a slight increase in magnitude, but this has provided no indication of reactivation.
Current activity corresponds to a period of unrest after a rash. This can last for weeks or even months. While volcanic activity is on the decline, there is the continued presence of hot spots near the surface, daily seismic activity, and persistent outgassing.

Lahar signals were observed: 4 on August 24, and 1 on August 25, related to the precipitation that was recorded during this period.
Clear weather conditions at the volcano on August 30 allowed excellent views of the crater and observations indicate that no major changes have occurred in the crater since the end of explosive activity on April 22.
There is a small, but not insignificant, possibility that magma activity will resume in the event of an influx of new magma from the depths.


The volcano remains at the ORANGE alert level.

 

Source: UWI-SRC 08.31.2021 / 1:00 p.m.

Nevado del Ruiz - sporadic gas and ash emissions on 08/30/2021 / 07:08 am - photo Ingeominas

Nevado del Ruiz - sporadic gas and ash emissions on 08/30/2021 / 07:08 am - photo Ingeominas

The Nevado del Ruiz, in unstable conditions, continues an activity characterized by constant degassing and sporadic ash emissions.
The gas-vapor plumes containing a certain amount of ash reached approx. 5,800 m above sea level and extended west-northwest of the volcano.
Seismic activity is mainly concentrated under the Arenas crater and under the NE and SE flanks of the volcano with a downward trend this week.


The alert level for the volcano remains at "yellow".


Sources: Servicio Geológico Colombiano, Ingeominas.

Fagradalsfjall - vent # 5 active in the fog 08.31.2021 / 2:01 p.m. - RUV webcam - one click to enlarge

Fagradalsfjall - vent # 5 active in the fog 08.31.2021 / 2:01 p.m. - RUV webcam - one click to enlarge

Fagradalsfjall - lava flows in three directions on 31.008.2021 - Photo VOLCAPSE - one click to enlarge

Fagradalsfjall - lava flows in three directions on 31.008.2021 - Photo VOLCAPSE - one click to enlarge

Some news from Fagradalsfjall, under heavy fog / cloud cover (no satellite images).

On August 31, the lava emitted by vent # 5 flowed mainly into Meradalur to the east, but also to Geldingadalur to the south, and Upper Meradalur to the southeast.

The activity remains fluctuating as shown by the variations of the tremor.

 

Sources: Hraun.vedur & Volcapse

Fagradalsfjall - tremor at 01.09.2021 - Doc. Hrau, .vedur.is

Fagradalsfjall - tremor at 01.09.2021 - Doc. Hrau, .vedur.is

Commenter cet article

Articles récents

Hébergé par Overblog