Etna update, 07.07.2023
Last week, strong gas emission continued to occur at Bocca Nuova. Occasionally, pulse-like gas releases were also visible. Today, around 19:26, a relatively strong pulse-like gas emission occurred, which was associated with a seismic signal. At the Southeast Crater complex, most of the gas was emitted from a vent in the northeast summit area of New Southeast Crater. Here, gas emissions were persistent and appeared more powerful than in previous weeks. Occasionally, gas was also emitted in pulses. From the central area between the old and the new South East Crater, gas was persistently emitted from fumaroles extending along the inner crater walls. Fractures on the upper north flank of New Southeast Crater also persistently released some gas and white steam.
I did not observe any gas emissions at Voragine and Northeast Crater.
The evaluation of the data from the GPS stations showed no significant changes for the period between 26.06. and 02.07. However, the data showed the continuation of the slight inflation phase of the volcanic edifice [1].
The signals from the clinometric stations showed no significant changes for the period between 26.06 and 02.07 [1].
After a slight increase in the number of infrasound events from 26 June, the infrasound activity at the summit craters slowly decreased again until 02 July. However, strong winds also affected the measurements during this time. The amplitude of the events was low. In most cases, Bocca Nuova could be identified as the source, although some events also occurred at Southeast Crater [1].
Sulphur dioxide emissions at the summit craters remained at a medium level in the week from 26.06. to 02.07..
During the same period, ground carbon dioxide emissions (ETNAGAS station) decreased significantly, but remained just at a medium level [1].
Last week, the online seismograms of station ECNE showed weak noise, as well as repeated various weak signals, some of which resembled explosion signals. These signals occurred about every 5 - 15 minutes. Today, two short sequences (2 - 3 min.) of stronger noise were recorded. The second event was associated with stronger gas emission from Bocca Nuova.
The tremor was at a medium level during the past week, with a slightly increasing trend [2].
In the period from 26 June to 02 July, the source of the tremor was below the southeast crater at a depth between 2400 - and 2900 m [1].
On 05.07. a series of earthquakes occurred in the area a few kilometres west of Bronte (west flank). The strongest quake had a magnitude of 4.0. The quakes occurred at a depth of between 9 and 30 km [3].
1. INGV-Sezione di Catania. 2023. Etna - Bollettino settimanale, 26/06/2023 - 02/07/2023
2. INGV-Sezione di Catania. 2023. Home. TREMORE VULCANICO. ECNE
3. INGV. Osservatorio Etneo. Sorveglianza e Monitoraggio. DATABASE TERREMOTI. Localizzazioni di sala operativa. 2023
