Etna update, 07/04/2023
During the past 14 days, gas emissions at Mt Etna continued to be concentrated at Bocca Nuova. Gas releases there were frequently intensified in a pulse-like manner. At the Southeast Crater complex, gas was persistently emitted from the central crater between Old and New Southeast Crater, as well as along the inner walls of the great breach. Gas also rose persistently from the northern summit area of New Southeast Crater. Very weak gas emissions occurred at Voragine and Northeast Crater.
As reported by INGV, in March the two vents on the crater floor of Bocca Nuova released gas persistently and in pulses. Sometimes gas rings were produced. Occasionally, thundering sounds were also heard. At the Southeast Crater complex, fumaroles released gas along the walls in the upper part of the fracture (large breach) created on 10.02.2022. Voragine and Northeast Crater continued to be blocked in March and showed only minor gas emissions [1].
Analysis of the data from GPS stations showed no significant changes for the month of March [1].
Clinometric data showed no significant changes in the slope of the volcanic edifice in March [1].
Due to strong winds, the measurement of infrasound activity at the summit craters was severely affected during the first half of March. Subsequently, low activity was recorded, with the intensity of the signals at low to slightly elevated levels. The source of the infrasound activity was Bocca Nuova [1].
Sulfur dioxide emissions at the summit craters were at intermediate levels in March and were subject to a sustained increasing trend.
Ground carbon dioxide emissions (ETNAGAS station) increased significantly in March and reached intermediate levels.
The concentration of helium isotopes (3He/4He - ratio) in the Etna area, last determined on March 14, was slightly lower than in the last measurements, with a value of 0.58. The measured value was at a high average level [1].
Online seismograms from the ECNE station showed sporadic, weak LP-signals during the last two weeks [2].
The tremor was at a medium level until 04 April, but then decreased significantly and is now at a low level [2].
In March, the source of the tremor was located between Bocca Nuova and Southeast Crater complex at an altitude of 1500 - 2500 m [1].
From 26.03. - 28.03. a pronounced series of weak earthquakes occurred in the area west of Solicchiata (northern flank), the strongest having a magnitude of 2.8. The quakes occurred at depths of 7 - 12 km. On 30.03. an earthquake of magnitude 1.7 was registered southwest of Bronte (western flank). On 04.04. an earthquake with a magnitude of 1.7 occurred in the area of the central crater [3].
1 - INGV-Sezione di Catania. 2023. Etna - BOLLETTINO MENSILE MESE DI RIFERIMENTO MARZO 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.
