Volcanic activity worldwide 4 Dec 2021: Etna volcano, Fuego, Popocatépetl, Semeru, Grímsvötn, Rev…

Map of today’s active volcanoes

Etna (Sicily, Italy): After a six weeks since the last strong eruptive episode (classified as paroxysm), it seems the activity to have picked up again.
The volcano observatory in Catania (INGV) reported that strombolian explosion started from the South-East crater at 16:10 local time today.
The instruments detected a strongly rising signal of volcanic tremor indicating rapid magma flux towards the surface, typical sign for an impending series of paroxysm in the coming days, weeks.

Grímsvötn (Iceland): Rapidly growing meltwater rate has reached 2220 cubic meters per second detected between 09:40 and 12:30 local time today and all estimated measurements indicate the upcoming glacial flood peak tomorrow.
A number of earthquakes have been recorded in the area associated with the ice-sheet and meltwater pathway.
Source: Icelandic Meteorological Office volcano activity update 4 December 2021
…4 Dec:
The meltwater rate has been increasing since the last update. The IMO’s hydrologists measured 1600 cubic meters per second at 10:15 and 12:20 local time today in Gígjukvísl.
The latest measurements confirm estimated forecasts and if continue to be in line with them, the glacial flood will likely reach its peak on Sunday. Based on the latest data, the maximum discharge rate is expected to be about 4000 m3/s.
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The ice sheet has continued to drop and reached already about 27 m in total subsidence.
Higher-than-usual gas emissions levels have been detected at the glacier rim of the volcano.

La Palma (Canary Islands (Spain)): The technical Director of the Civil Protection’s volcanic emergency plan (PEVOLCA), Miguel Ángel Morcuende explained in the latest press conference about the status of the volcanic eruption, that the new lava flow at the southern margin of the flow field was advancing in southwesterly direction towards Camino La Majada, covering land that was left untouched between the previous lava flows labeled #3 and #11, but has long since been evacuated.
Initially fast-flowing, the new lava flow has slowed down by now, as it lost fluidity along its path.
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Other lava flows, namely #7, 8 and 10 continue also be alimented, but less than during the past days. No lava is currently arriving at the sea deltas.
At the vents, activity has been much lower today, too. Lava fountaining ceased it seems, replaced by more intermittent and weaker strombolian activity. Ash emissions have been less vigorous and also discontinuous today, but still produced low plumes that reached approx. 2,000 m altitude and drifted in westerly directions over the Atlantic.

…4 Dec:
As feared by the inflation signal in the past days, the relative calm at the volcano has come to an end and new magma arrived at the vents earlier, causing another overflow of lava.
Most notably new lava flow has started on the southern side of the eruption area to advance westwards through new land. It has already reached the Camino Real de Todoque and is descending parallel to Camino Aniceto and Camino La Majada roads.
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On his way, more houses, plantations and roads were destroyed. The arrival of the lava flow in the Las Norias area is imminent.
Aerial video by the municipality of El Paso:

Suwanose-jima (Ryukyu Islands): (4 Dec) Volcanic Ash Advisory Center Tokyo (VAAC) issued the following report: ERUPTED AT 20211204/0625Z OVER FL060 EXTD S OBS VA DTG:04/0620Z

Semeru (East Java, Indonesia): A terrible video of turbulent hot gravity-driven pyroclastic flows where people run off to save their lives was published by a local observer in social media.
The powerful eruption triggered massive block and ash flows from the partially collapsed lava dome creating billowing ash plume up to 40,000 ft (12 km) altitude today.
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Airlines have been warned of an ash cloud rising up to 15,000m (50,000 ft).

…4 Dec:
According to the Indonesian Civil Protection (BMKG), the eruption occurred at 15:20 local time, and affected the areas of the Oro Oro Ombo, Besuk Kobokan, Desa Sapiturang, and Pronojiwo villages in the Lumajang district of East Java. Officials told in a news conference that at least one person had died and 41 people had suffered burn injuries.
Unfortunately, the death toll might still rise, given the scale of the eruption and population density in the area. The many people who suffered burns were only lucky not to be killed. This is a typical hazard for people and animals caught in the not-yet lethal outer parts of pyroclastic currents.
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Authorities are setting up evacuation tents, but search and rescue efforts are difficult due to the thick ash in the area.
BMKG stated in a tweet that the flows reached lengths of „500-800 meters“, but this is likely to be read 5,000-8,000 meters – the summit of the volcano along stands about 3000 m above the nearest villages and from imagery, the maximum distance of the hot avalanches is likely to be in the range of 5-10 km.

…4 Dec:
A massive eruption occurred from the volcano this afternoon at around 4.25 p.m. local time, producing a large pyroclastic flow (hot avalanche of ash and rock particles) that traveled down the southern slopes, as well as producing an ash column that rose to estimated 40,000 ft (12 km) altitude.
From videos and photos circulating on social media, the pyroclastic flow reached farmland but also inhabited areas, and it must be feared that it claimed victims and caused extensive damage.
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We will update on this as soon as more precise information becomes available.
Judging from the imagery, the most likely scenario is that a large portion of the accumulated lava dome in the breached summit crater has collapsed into a violent avalanche, maybe triggered by or triggering a vertical explosion. The lava dome had been moderately active and slowly growing for years, at varying intensity. The event of today apparently came as a surprise, but such dome collapse events can usually not be predicted when they occur.

Semisopochnoi (United States, Aleutian Islands): Volcanic Ash Advisory Center Anchorage (VAAC) issued the following report: LOW-LVL EMISSIONS.

Popocatépetl (Central Mexico): Volcanic Ash Advisory Center Washington (VAAC) issued the following report: STEAM ONLY

Fuego (Guatemala): (3 Dec) Volcanic Ash Advisory Center Washington (VAAC) issued the following report: VA EMS HAVE DISP IN STLT IMAGERY

Nevado del Ruiz (Colombia): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 22000 ft (6700 m) altitude or flight level 220 and is moving at 5 kts in W direction.
The full report is as follows: CONT VA EMS OBS to 22000 ft (6700 m)

Sangay (Ecuador): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 20000 ft (6100 m) altitude or flight level 200 .
The full report is as follows: VA AND GASES SEEN IN SAT to 20000 ft (6100 m)
…4 Dec:
The activity at the volcano has been increasing during the past two days.
An intensified trend of activity is also shown in the continuous rise of seismic activity detected by the volcano observatory.
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A swarm of long-period earthquakes has been detected by the SAGA seismic network at 16:00 local time on 1 December which indicated elevated fluid movements of gas, water and magma under the surface. Earthquakes became more frequent in numbers (60 per hour) and strength including periods of high amplitude tremor.
As the activity has been increasing further, a new lava flow started to descend on the north flank.

Reventador (Ecuador): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 15000 ft (4600 m) altitude or flight level 150 .
The full report is as follows: POSS VA SEEN IN SAT to 15000 ft (4600 m)

Sabancaya (Peru): Volcanic Ash Advisory Center Buenos Aires (VAAC) issued the following report: UNABLE TO DETECT

Nevados de Chillán (Central Chile): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Buenos Aires warned about a volcanic ash plume that rose up to estimated 12000 ft (3700 m) altitude or flight level 120 and is moving at 5 kts in NE direction.
The full report is as follows: INTERMITTENT EMISSIONS to 12000 ft (3700 m)

Strombolian activity at Etna volcano tonight (image: Boris Behncke/twitter)