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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
Sangay - 12/02/2021 / 12:02 - IGEPN webcam

Sangay - 12/02/2021 / 12:02 - IGEPN webcam

Sangay - image Sentinel-2 bands 12,11,8A from 12/02/2021 / 3:36 p.m. - via Mounts project

Sangay - image Sentinel-2 bands 12,11,8A from 12/02/2021 / 3:36 p.m. - via Mounts project

After registration on December 1 from 4 p.m. loc. by the SAGA seismic station located SW of the Sangay volcano of a swarm of earthquakes of very similar shape and characteristics, and increasing from 32 events per hour to 60 events per hour around midnight, the IGEPN reports at 04:03 loc. on December 2 a major explosion.

Therefore, there is a possibility of ash fall in the areas west and southwest of the volcano, in the province of Chimborazo. It is recommended to take the relevant measures and receive the information from official sources.

Sangay - seismogram of the SAGA station at 12/02/2021 / 04:03 am loc. - Doc. IGEPN

Sangay - seismogram of the SAGA station at 12/02/2021 / 04:03 am loc. - Doc. IGEPN

Sangay - Volcanic Ash advisory at 12/02/2021 11:32 a.m. - Doc. VAAC Washington

Sangay - Volcanic Ash advisory at 12/02/2021 11:32 a.m. - Doc. VAAC Washington

From 04:40 TL, thanks to satellite images from VAAC Washington, 3 ash clouds are observed; the first reaches 10 km above the crater and the second 7 km above the crater (flight altitudes 500 and 400), with both emissions heading west. The third ash cloud, reaching an altitude of 1770 meters above the crater, moved north-west.

Thermal anomalies are reported by the FIRMS and Mirova stellites. This December 3 at 3.20 am, an anomaly of VRP 424 MW was reported.

Seismicity is characterized by 1470 LP earthquakes, 100 explosion earthquakes, and 72 tremor episodes.

 

Source: IGEPN, VAAC Washington & Mirova

Nyiragongo - incandescence in the crater - via Ch. Balagizi 30.11.2021

Nyiragongo - incandescence in the crater - via Ch. Balagizi 30.11.2021

Thermal anomalies have been observed at Nyiragongo since November 25.

Mirova reports them between VRP 3 and 230 MW, depending on the activity and the cloud cover disturbing the measurements.

Nyiragongo thermal anomalies at 12/02/2021 / 11:45 p.m. - Doc. Mirova_MODIS_logVRP

Photos of Charles Balagizi of the GVO attest to the presence of lava.

 

Sources: Mirova and Charles Balagizi.

Nyiragongo - Spattering in the crater - via Ch. Balagizi 30.11.2021

Nyiragongo - Spattering in the crater - via Ch. Balagizi 30.11.2021

The activity of Cumbre Vieja declined on December 2 between an activity of the vent of the NE flank, with periods of rest, followed by resumption of strombolian activity and a period of phreatomagmatic activity (supposed) of the principal cone producing a very dense ash cloud.

La Palma - Cumbre Vieja- jet of pyroclasts at 400-500 m. high by the secondary vent - photo InVolcan 02.12.2021

La Palma - Cumbre Vieja- jet of pyroclasts at 400-500 m. high by the secondary vent - photo InVolcan 02.12.2021

For a few minutes from 3:00 p.m. on December 2, a decrease in pyroclast emission is observed in the secondary cone of the Cumbre Vieja eruption, coinciding with a tremor drop (the first peak of RSAM drop was a cut data at 8:30).

Then the activity is returned to Strombolian type around 6 p.m. local, with a strong emission of pyroclasts which make the secondary cone grow.

The height of the jet on the evening of December 2 reached a maximum of 400-500 m.

La Palma - Seismicity at 02.12.2021 / 06h57 - Doc. IGN

La Palma - Seismicity at 02.12.2021 / 06h57 - Doc. IGN

La Palma / Cumbre Vieja - the decrease in the emission of pyroclasts is observed in the secondary cone - 02.12.2021 / 3pm - Doc. Itahiza - one click to enlargeLa Palma / Cumbre Vieja - the decrease in the emission of pyroclasts is observed in the secondary cone - 02.12.2021 / 3pm - Doc. Itahiza - one click to enlarge

La Palma / Cumbre Vieja - the decrease in the emission of pyroclasts is observed in the secondary cone - 02.12.2021 / 3pm - Doc. Itahiza - one click to enlarge

La Palma - RSAM at 02.12.2021 / 15:45 (the first peak of decline of RSAM was a data cut at 8:30) - Doc. IGN

La Palma - RSAM at 02.12.2021 / 15:45 (the first peak of decline of RSAM was a data cut at 8:30) - Doc. IGN

The main lava flow passes through the central area of ​​previous flows, over an already affected area, without causing additional damage. Air quality remains at good levels and the airport is operational. Regarding seismicity, an increase occurs at intermediate depths, localizing in the same areas.

 

Sources: IGN, InVolcan, DSN

La Palma / Cumbre Vieja eruption - situation on 02.12.2021 - Doc. ERCC / European Commission - one click to enlarge

La Palma / Cumbre Vieja eruption - situation on 02.12.2021 - Doc. ERCC / European Commission - one click to enlarge

The current flooding of the jökulhlaup could be followed by a volcanic eruption of the Grimstvötn, and authorities must be prepared, says geophysics professor Magnús Tumi Guðmundsson. Grímsvötn is Iceland's most active volcano and its last eruption dates back to 2011 and 2004.

The volcano's current inflation is greater than it was for the 2011 eruption, so the plumbing system is likely stuffed with magma, according to Dave MacGarvie.

With the flow of water, and the collapse, this could be enough to lighten the load at the top of the magma chamber for an eruption to erupt, as last happened in 2004.

To watch this weekend.

 

Sources: RUV and specialist comments

Grimstvötn - jökulhlaup and gauge socket (image in the rearview mirror) - photo 02.12.2021 Njáll Fannar Reynisson - Veðurstofan

Grimstvötn - jökulhlaup and gauge socket (image in the rearview mirror) - photo 02.12.2021 Njáll Fannar Reynisson - Veðurstofan

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