Beginning of eruption at Piton de la Fournaise on December 22, 2021.
The OVPF provides information in its daily bulletin:
Number of volcano-tectonic earthquakes (VT) of 21-12-2021: 583
Zone affected by VT: Summit cone - Volcano-tectonic earthquake of greater magnitude of 12/21-2021: Duration: 25.92 s - Magnitude of duration: 1.96
Following a seismic crisis detected at around 1:15 a.m., the volcanic tremor synonymous with the arrival of magma near the surface has been recorded since around 3:30 a.m. local (11:30 p.m. UT). According to OVPF records, the source of this tremor is located on the southern flank in the Enclosure. At least 3 eruptive cracks have opened on the southern flank of the volcano. This eruption is visible on the Piton de Bert trail (southern sector of the volcano)
Taking into account the presence of hot and incandescent gases, and the possibility of emission of lava in the short term, the Prefect decided to implement the alert phase 2-1 "eruption in progress in the enclosure" of the specific ORSEC * volcano device this Wednesday, December 22 at 4:00 a.m.
Public access to the Fouqué enclosure, from the Pas de Bellecombe path or any other path, as well as landing aircraft in the volcano area, are prohibited until further notice.
Source: OVPF- IPGP
Piton de La Fournaise - Illustration of the deformation over 1 year (22.12.2020 - 22.12.2021). The baselines (variation in distance between two GPS receivers) crossing the Piton de la Fournaise building, at the top (top), the base of the terminal cone (in the middle) and in the far field (bottom) are shown here. ) (see location on the associated maps). An increase is synonymous with elongation and therefore swelling of the volcano; conversely, a decrease is synonymous with contraction and therefore deflation of the volcano. Any periods colored in light pink correspond to eruptions. - Doc. OVPF
Piton de La Fournaise - 12.22.2021 - location of the eruptive site - Doc. Imazpress Réunion - one click to enlarge
Taaniela Kula, the chief geologist for Tonga, confirmed that yesterday's eruption of volcanic ash and dust occurred between 9:30 a.m. and 9:40 a.m., originating from Hunga Ha'apai, determined from NOAA satellite images / CIMSS HIMAWARI 8 AHI.
The eruption first reached 3-16 km altitude in a mushroom formation with a radius of 30 km, and during the remainder of the day reached 18 km altitude on the 'Otu Mu'omu'a and 'Otumotu Lulunga from Ha'apai, as well as' covering Tongatapu and' Eua.
At 4:40 p.m. on December 20, the ash / dust eruption maintained an altitude of 18 km and reached the Vava'u Islands, including Fonualei Island. At 7:00 p.m. it reached Niuafo'ou Island and beyond. At 9:00 p.m., it reached Niuatoputapu and Tafahi Islands, he said.
The ash cloud cleared on December 21, but gaseous emission continued with cloud formation drifting over Tonga.
All Tongan residents have been urged by geologists this evening to protect their water reservoirs from possible acid rain, until the volcanic eruption ceases.
Source: Matangi Tonga Online
Hunga Tonga-Hunga Ha'apai - the eruption seems to have adopted the site of the last manifestation of the volcano - photo Maxar sat. 22.12.2021
In view of the monitoring data of Vulcano by the INGV during the week of December 12 to 19, 2021 (issued on December 21), it is highlighted:
The temperature values continue to show a decreasing trend on the rim of the crater while they remain stable on the inner face.
The values of CO2 flux on the ground in the summit area (VCSCS) show a downward trend, while remaining high.
The flow of SO2 in the crater area appears at a high level
Geochemistry of fumarolic gases: The concentrations of magmatic species (CO2, He) are at high levels.
The flux values at the base of the cone, acquired automatically by the VULCANOGAS network, are at high values. For the Faraglione site, the recorded values can be considered as typical of the site background.
Geochemistry of thermal aquifers: The physicochemical parameters are stable at the Sicilia and Bambara Camping sites.
Local seismicity: The phase of increase of low frequency events (VLP) has been interrupted which anyway have a high frequency of occurrence.
Regional seismicity: No earthquake with Ml> = 1.0 was located last week in the Vulcano region
Deformations - GNSS: The GNSS network does not show substantial variations.
Deformations - Clinometry: The clinometric network shows a tendency to enter into the deformations observed during the last months.
Gravimetry: The localized gravity variations at the VSOCR continuous station are recorded. There are no variations attributable to significant phenomena of deep mass redistribution.
Monthly CO2 flow campaign: there is a general decrease in CO2 emissions in the Vulcano Porto area; the flow of CO2 emitted by the soil goes from 420 t / d on 11/10/2021 to 310 t / d on 12/14/2021.
Monthly well campaign: a slight decrease in the temperature values of the dissolved carbonate species is observed in all the monitored wells.
GB-RAR: The results of the GB-RAR monitoring referring to the period from December 14 to 21, show a general stability of the area, with deformations along the LOS of less than 1 mm.
The December 20 videoconference meeting in Vulcano, attended by INGV, Civil Protection, ARPA and Ispra, did not result in a final decision. Participants agreed to a "extension" for a few days of the ordinance that prohibits residents of Vulcano Porto from sleeping in their homes, except those with upstairs bedrooms. This new deadline will allow additional ground CO2 measurements to be carried out in 10 homes using special equipment due to arrive on the island today.
Sources: INGV OE and regional press
After a three-month hiatus, the eruption of Fagradalsfjall volcano is considered officially over, Icelandic authorities were told on Monday. "It has been three months since there was no lava effusion, so the eruption is considered to be over," an official from the Icelandic Meteorological Institute (IMO) told AFP. Bryndís Yr Gísladottir.
A new seismic swarm has been detected since December 21 in the Reykjanes Peninsula. On December 21, 2021 at 6 p.m., the earthquakes began about 2-4 km northeast of Geldingadalur. Activity increased significantly at 12:30 am at night and is still strong with 1-10 earthquakes per minute. As the night progressed, the activity shifted to the volcanoes of Geldingadalur. It is not unlikely that the magma will flow, which means that the magma is moving horizontally in the earth's crust. There is no sign of a rash.
Sources: IMO and vedur.is