Etna update, 30/12/2022:
During the past week, effusive activity continued at the northeastern base of the New Southeast Crater. Several partial flows poured over the fan-shaped lava field in a northeasterly direction, crossed the Valle del Leone and reached the edge of the Valle del Bove. There they moved as several tongues in an easterly direction down the steep slope and formed an ever-widening lava field. The fronts of the tongues stagnated at 2100 - 2300 m altitude in the area southwest of Monte Simone.
Furthermore, I could not observe any explosive activity in the area of the effusive vents or in the summit area of New Southeast Crater.
At Bocca Nuova, pulsating gas emission continued. No significant gas emission was visible at Voragine and Northeast Crater.
As INGV reports, the front of the lava flow reached 2150 m high terrain on 25 December. Using MODIS/VIIRS satellite data, the volume of lava released so far could be estimated at 1,200,000 - 2,400,000 m3. The data also show that the production rate has increased from about 20 December, rising from about 1 m3/s initially to about 2 - 2.5 m3/s [1].
Analysis of the data from the GPS stations showed no significant changes between 19 and 25 December [1].
The clinometric data showed no significant changes between 19 and 25 December [1].
Infrasound activity at the summit craters was low during the period from 19 to 25 December. The source of the activity was Bocca Nuova [1].
Sulphur dioxide emissions at the summit craters decreased in the period between 19 and 25 December and reached medium levels.
Ground carbon dioxide emissions (ETNAGAS station) remained at a medium level between 19 and 25 December.
The concentration of helium isotopes (3He/4He - ratio) in the Etna area, which was last determined on 15 December, was higher than in the last measurements with a value of 0.64. High levels have now been reached again [1].
The online seismograms of station ECNE continued to be overlaid by noise caused by the persistently elevated tremor last week [2].
The tremor decreased somewhat on 24 December, but continued to hover at medium levels [2].
The source of the tremor between 19 and 25 December was in the area between Southeast Crater and Bocca Nuova at an altitude between 2500 and 2800 m [1].
On 23.12. a quake with a magnitude of 1.6 occurred in the area southeast of Case del Vescovo (southeast flank). On 23.12. a quake with a magnitude of 1.8 was measured on Monte Scorsone (east flank). On 25.12., a quake of magnitude 1.6 occurred southeast of Fiumefreddo di Sicilia (eastern flank) [3].
1 - INGV-Sezione di Catania. 2022. Etna - BOLLETTINO SETTIMANALE - SETTIMANA DI RIFERIMENTO 19/12/2022 - 25/12/2022
2 - INGV-Sezione di Catania. 2022. Home. TREMORE VULCANICO. ECNE
3 - INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2022.
Photo by INGV
