December 28 , 2021.

La Réunion Island , Piton de la Fournaise :

Press release of December 28, 2021 – 9:45 a.m.

The eruption that began on December 22, 2021 at around 3:30 a.m. local time continues. Over the last 24 hours the amplitude of the eruptive tremor (indicator of an emission of lava on the surface) shows less rapid fluctuations than the previous days.
The amplitude of the tremor is this morning at about 35% of its initial amplitude.

The fluctuations observed can be linked either to:
– the cone under construction which undergoes construction and dismantling phases, thus influencing the speed of the lava flows at the level of the vent;
– or to punctual releases of pockets of gas trapped in the supply ducts which can be released suddenly leading to an increase in the tremor.
The relative stabilization of the tremor, perhaps linked to the consolidation of the cone, which has now reached a size making it more stable.

The lava tunnel activity set up at the foot of the cone since December 23, 2021, thanks to the closure of the cone, continues, with occasional resurgences of flows. Lava fountain activity within the cone is low, and lava fountains exceed the height of the cone (<15m) only intermittently.

Over the last 24 hours:
– Two volcano-tectonic earthquakes under the summit were recorded.
– Surface deformations no longer show significant deformation.
– The lava flow estimates, established by satellite method with the HOTVOLC platform (OPGC – Clermont Auvergne University), are between 2 and 8 m3 / sec. These variations are explained by the method, which is based on the infrared radiation of the flow, the perception of which by satellites can be largely influenced by the weather conditions above the flows.
– The front of the flow, in graton, currently on a relatively flat area, does not seem to have progressed significantly since yesterday.

Alert level: Alert 2-1 (eruption in the Enclos )

Source and graphic : OVPF / IGPG.

Photo : PGHM via OVPF.

Peru , Sabancaya :

Analysis period: from December 21, 2021 to December 27, 2021, Arequipa, December 28, 2021.
Alert level: ORANGE

The Geophysical Institute of Peru (IGP) reports that the eruptive activity of the Sabancaya volcano remains at moderate levels, that is to say with the recording of an average of 27 daily explosions, with columns of ash and gas up to 2.5 km altitude above the summit of the volcano and their consequent dispersion. Therefore, for the following days, no significant change is expected in eruptive activity.

The IGP recorded and analyzed the occurrence of 512 earthquakes of volcanic origin, associated with the circulation of magmatic fluids within the Sabancaya volcano. An average of 27 explosions was recorded daily. During this period, Volcano-Tectonic (VT) earthquakes associated with rock fracturing were localized mainly in the Northwest, North, and East of Sabancaya and presented magnitudes between M 1 , 9 and M 2.9.

The monitoring of the deformation of the volcanic structure using GNSS techniques (processed with fast orbits) does not present any significant anomalies. However, in general, an inflation process was observed in the northern sector (around the Hualca Hualca volcano). Visual surveillance identified columns of gas and ash up to an altitude of 2.5 km above the summit of the volcano, which were scattered towards the southern, southwest and southeast sectors of Sabancaya. Satellite recordings have identified the presence of 2 thermal anomalies (maximum value of 4 MW) associated with the presence of a lava body on the surface of the volcano’s crater.

RECOMMENDATIONS
• Keep the volcanic alert level in orange.
• Do not approach within a radius of less than 12 km from the crater.

Source : IGP

Photo : Auteur inconnu.

Iceland , Peninsule de Reykjanes :

Since midnight around 400 earthquakes have been detected, which is a lot more than at the same time yesterday. Yesterday on December 27th at 12:31, an earthquake M3.0 was measured about 2 km W of lake Kleifarvatn. There the same morning at 08:25 an earthquake of magnitude M3.6 was measured. These earthquakes are interpreted as triggered earthquakes due to increased pressure caused by a dike intrusion near Fagradalsfjal

Yesterday around 2200 earthquakes were detected and the activity has slowed down a bit. The 21st of December an earthquake swarm started by Fagradalsfjall volcano, since then around 19000 earthquakes have been automatically detected, thereof 14 larger than M4.0.

Note, that the triggered earthquakes can set loose rocks and small landslides. Travelers are therefore urged to show caution in steep hillsides.

Source : Vedur is.

Hawaii , Kilauea : 

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary: 
The summit eruption of Kīlauea Volcano—within Halemaʻumaʻu crater—remains paused, after lava effusion dwindled on December 25 following a strong deflationary event. Based on similar eruptive pauses in recent weeks, the return of inflationary tilt last night suggests that lava effusion may resume sometime in the next 24 hours. All recent lava activity has been confined to the crater, and there are no indications of activity migrating elsewhere on Kīlauea.

Summit Observations:
Rapid inflationary tilt began just before midnight last night; the trend continues at this time and has recovered most of the tilt lost during the prior deflation. Volcanic tremor associated with the eruption is currently not detectable and earthquake activity in the summit region remains below background level. A sulfur dioxide (SO2) emission rate of approximately 5,300 tonnes per day was measured on December 24, when eruptive activity was more vigorous before the pause.

Halemaʻumaʻu Lava Lake Observations:
Lava is not presently erupting from the western vent within Halemaʻumaʻu crater. The surface of the lava lake is mostly crusted over, except for a small section north of the western vent measuring less than 50 meters (164 feet) in diameter. The lake has seen a total rise of about 70 meters (230 feet) since lava emerged on September 29.

Source : HVO

Photo : USGS / D. Downs .

Costa Rica , Turrialba / Poas / Rincon de la Vieja :

Turrialba volcano

No eruption is reported.
Seismic activity is similar, compared to yesterday.
At the time of this report, the winds are blowing from the west.

There are no eruptions or volcanic tremors. The atmospheric conditions do not allow observing the summit. Seismicity was maintained with frequent low-frequency volcanic earthquakes and a few proximal volcano-tectonic earthquakes. The gases emitted are kept at a stable level, with less than 10 parts per million of SO2 per unit of air. No significant deformation of the volcanic building is observed.

Poas volcano

No eruption is reported.
Seismic activity is similar, compared to yesterday.
At the time of this report, the winds are blowing from the west.

There are no eruptions or volcanic tremors. The weather conditions do not allow observing the summit. Seismicity was maintained with frequent volcanic earthquakes of low frequency and very low amplitude. Officials from the Poás Volcano National Park report a sound sequence in the lake at 2:50 p.m., which could be associated with a one-block fall from the crater wall, similar to what was observed on November 3 of this year. At this time, no associated seismic or sound activity was recorded in the monitoring equipment, but the lake could not be observed due to the cloudiness. The evolved gas level is lower than the detection level of the equipment. Slight inflation persisted.

Rincón de la Vieja volcano

No eruption is reported.
Seismic activity is similar, compared to yesterday.
At the time of this report, the winds are blowing from the west.
No eruption is recorded. The atmospheric conditions do not allow observing the summit. After yesterday’s eruption at 10:15 a.m., the tremor weakened until it disappeared, however, this morning at 3 a.m., a low frequency shake (between 0.8 and 3 hz) was again recorded , which has remained stable so far. There are no low frequency volcanic or volcano-tectonic earthquakes. The volcanic building remains stable.

Activity report of the Rincón de la Vieja volcano, December 25, 2021.

On December 25, 2021 at 10:23 a.m. local time, an eruption was recorded on the Rincón de la Vieja volcano, the height reached by the column is unknown due to the visibility conditions of the site.

Ash fall is reported in: No ash fall is reported
Sulfur odor is reported in: No sulfur odor is reported

Source : Ovsicori.

Photos : RSN , Archive Ovsicori , Raul Mora / RSN / UCR.