Etna update, 13/01/2023:
Last week, lava emission continued at the effusive vent at the northeast base of Mt Etna's New Southeast Crater. Different partial flows continued to be fed, moving through a system of tunnels and channels to the rim of the Valle del Bove. There, the fronts of two or three lava flows stagnated at about 2100 m above Monte Simone. From 08 January, the tongues retreated. Bad weather with fresh snow hampered observations until 10 January. From 11 January visibility was very good again and the hot, fan-shaped lava field stood out very well as a dark area on the snow-covered mountain. During the day, the fronts of the lava tongues descended again a little further down the slope and reached about 2200 m high terrain.
On 12 January, the southernmost lava tongue advanced even further down the slope, but then stagnated today at about 2100 - 2200 m high terrain.
Meanwhile, the usual gas emissions continued at the summit craters of Etna, which were still strongest at Bocca Nuova. During the nights, however, I could no longer observe any glow there. On the other hand, from 11 January onwards, some glow appeared on light sensible webcams in the upper northern summit area of New Southeast Crater. This was probably caused by rising heat or high-temperature fumaroles.
As reported by INGV, the front of the most advanced lava flow reached 2170 m high terrain between 04 and 07 January. The average production rate could be estimated at about 3 m3 lava/s with the help of satellite data. On 07 January, the volume of lava produced since the beginning of the eruption on 27.11.2022 was calculated to be about 2.5 - 4.3 million m3 [1].
The evaluation of the data from the GPS stations showed no significant changes between 02 and 08 January. However, the slight trend towards deflation of the volcanic edifice continued [1].
The clinometric data showed no significant changes in the slopes of the volcano between 02 and 08 January [1].
The infrasound activity at the summit craters was characterised by a relatively high frequency of events in the period from 02 - 08 January. However, the amplitude was low, indicating weak to moderate activity. The source of the events was Bocca Nuova [1].
The sulphur dioxide emissions at the summit craters decreased slightly in the period between 02 and 08 January compared to the previous week and were in the lower medium level.
Ground carbon dioxide emissions (station ETNAGAS) remained at a medium level between 02 and 08 January and were subject to only minor fluctuations [1].
The online seismograms of station ECNE showed occasional weak explosion signals or long-period signals during the past week.
The tremor was initially still on the border between low and medium levels last week, but then rose again somewhat from 10 January and has been slowly decreasing since then [2].
Until 05 January, the source of the tremor was located at an altitude of 2700 - 2900 m in the area between Southeast Crater and the effusive vent. From 05 January on a shift to the area northwest of Southeast Crater at an altitude of 2300 - 2700 m was detected [1].
On 07.01. a quake of magnitude 1.5 was recorded in the area of Grotta del Gelo (northern flank). On 12.01., two earthquakes with magnitudes of 2.3 and 1.9 were recorded near Biancavilla (southern flank) [3].
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 02/01/2023 - 08/01/2023
2 -INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2023.
