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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
 Soufrière de St. Vincent - the plume of the explosive eruption of 22.04.2021 / 11:08, at the start of its development, seen from Belmont. - Doc. UWI-SRC

 Soufrière de St. Vincent - the plume of the explosive eruption of 22.04.2021 / 11:08, at the start of its development, seen from Belmont. - Doc. UWI-SRC

At the Soufrière of St. Vincent, small long-lived and hybrid earthquakes continued to be recorded, their rate of occurrence gradually increasing on April 22.
The high-level seismic tremor began at 11:09 a.m., generated by explosive activity, and lasted for approximately 20 minutes.

A vertical explosive eruption plume slowly rose above the crater, eventually reaching a height of around 8,000 meters
During the initial stages of the explosion, a base surge (pyroclastic density current, PDC) was observed descending the western flank of the volcano.
The tremor continued, at a lower level, for the next two hours as La Soufrière continued to evacuate ash.

Since the initial depressurization noted immediately after the explosive phase of April 9, the continuous GPS network has recorded a decrease in overall horizontal and vertical speed rates.
movement.
The volcano continues to erupt. Its pattern of seismic activity over the past few days is typical of the growth and destruction of lava domes.
Explosions accompanied by falling ash, of similar or larger size, may occur with little or no warning affecting Saint-Vincent and neighboring islands.
The volcano is at the Red alert level.

 

Source: UWI-SRC -22,04,2021 / 18h

Pacaya - morning meeting of villagers to observe the advance of lava flows - Doc. EPA / via RUV 23.04.2021

Pacaya - morning meeting of villagers to observe the advance of lava flows - Doc. EPA / via RUV 23.04.2021

The inhabitants of the villages near the Pacaya volcano in Guatemala wonder every morning if the lava flows from the mountain will reach the villages. An eruption began in the mountain in February when a crack formed on the side of the volcano.

The Pacaya presents a degassing interspersed with ash plumes at 2,800 meters above the crater, dispersing to the south and southwest with ash fallout. The lava flow on the western flank remains active, without significant advance, and exhibits high temperatures and gaseous fumes at various points in its path.

According to a resident of El Patrocinio, the lava flow towards the village stopped three days ago. She says the townspeople are hoping the lava will just stay there. If the lava continues to move towards the village, the inhabitants, numbering about 350, may have to move. The authorities told the villagers about their settlement in an area about 160 km away.

 

Sources: Insivumeh and EPA

Sangay - ash plume of 04.22.2021 - photo Pablo Arias via Rizal

Sangay - ash plume of 04.22.2021 - photo Pablo Arias via Rizal

This morning, April 22, an emission of gas and ash from the Sangay volcano, in Ecuador, was observed on the GOES-16 satellite. This emission is directed towards the west of the volcano and there is a probability of ash fall in some populations of the provinces of Chimborazo, Bolivar and Los Ríos. It is recommended to take the necessary precautions.

 

Sources: IGEPN, RAMMB & NOAA / CIMSS

Sangay - 04.22.2021 / 10am - GOES-16 satellite images - Doc. RAMMB & NOAA / CIMSS - one click to enlargeSangay - 04.22.2021 / 10am - GOES-16 satellite images - Doc. RAMMB & NOAA / CIMSS - one click to enlarge

Sangay - 04.22.2021 / 10am - GOES-16 satellite images - Doc. RAMMB & NOAA / CIMSS - one click to enlarge

In the Reykjanes Peninsula, between 500 and 600 earthquakes were detected in the same area and a magnitude 4.1 earthquake was measured on the night of April 20 at 11:05 p.m., northeast of Grindavík, just north- east of the Blue Lagoon. It was followed by a replica of M3.2.

The seismic swarm area northeast of Grindavik is centered around an older fissure or row of craters (in green on the ISOR geological map)

Reykjanes Peninsula- seismic swarm area NE of Grindavik centered on an old fissure or row of craters (in green- near Svatsengi) - ISOR map 22,04,2021 via Óróapúls - one click to enlarge

Reykjanes Peninsula- seismic swarm area NE of Grindavik centered on an old fissure or row of craters (in green- near Svatsengi) - ISOR map 22,04,2021 via Óróapúls - one click to enlarge

Reykjanes Peninsula - magnitude of the earthquakes at 04/22/2021 / 5:10 p.m. - Doc. IMO

Reykjanes Peninsula - magnitude of the earthquakes at 04/22/2021 / 5:10 p.m. - Doc. IMO

There has been speculation that a new eruption opening opened in the eruption area around the time the earthquake was felt, but nothing has yet become clear in this regard.
Voltage changes occur in the region, which is a bit of Geldingadalur, and these earthquakes trigger earthquakes which were also measured in the period before the eruption of Geldingadalur. According to Bjarki Kaldalón Friis, a nature conservation specialist at the Meteorological Office, there are few signs that eruption cracks will open in the area, but scientists are watching closely.
At today's civil defense meeting, the seismic activity was discussed and several nature conservation experts from the Meteorological Bureau visited to study the activity and measure the temperature in the cracks.

 

Sources: IMO, ISOR, Óróapúls - Volcanism in Iceland

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