Mount Etna's current eruptive phase is continuing to change shape. INGV-OE has documented repeated effusive activity at different elevations, lava advancing into Valle del Bove, and continuing explosive and ash-producing activity at Voragine. The latest change came early on 17 August, when surveillance cameras recorded the opening of another effusive vent between about 2,200 and 2,350 metres above sea level.
At 06:09 UTC on 17 August, INGV-OE recorded the opening of an effusive vent in Valle del Bove. The new opening produced a lava flow while ash emission from Voragine continued towards the south-east.
Another vent opens in Valle del Bove
INGV's Osservatorio Etneo reported the new opening in a communiqué issued at 07:18 UTC on 17 August. Surveillance-camera imagery showed that an effusive vent had opened at 06:09 UTC in Valle del Bove, at an elevation between approximately 2,200 and 2,350 metres. The vent was producing a lava flow, and INGV-OE staff were carrying out field surveys to assess the new activity.
At the same time, activity at the summit had not stopped. INGV reported continuing ash emission from Voragine, with the ash dispersing towards the south-east. The combination of lava emission lower in Valle del Bove and continuing summit ash emission is the defining feature of the latest update.
The eruption has repeatedly changed through the summer
The 17 August opening is the latest development in a sequence that has repeatedly changed. On 26 June, INGV field observations identified effusive activity in the upper Valle del Leone — the upper Valle del Bove — at around 3,000 metres elevation. INGV's subsequent weekly bulletin placed the source vent at about 3,030 metres. By 27 June it was feeding a lava flow about 630 metres long, with the most advanced front near 2,780 metres elevation.
By 2 July, the 3,030-metre source was still feeding overlapping lava flows and the most advanced front was estimated near 2,620 metres. Variable Strombolian activity was also continuing from a pit on the upper flank of Voragine. INGV declared the previously reported phenomena ended on 8 July.
Another effusive phase then began in the upper Valle del Leone on 30 July. INGV confirmed on 2 August that this activity had ended and the associated lava flows were cooling. Activity subsequently intensified again during August. By 10 August, INGV field observations placed the most advanced active lava front beyond Rocca delle Palombe at approximately 1,370 metres elevation, while intense explosive activity and abundant ash emission continued at Voragine.
Several openings does not mean every vent is active
INGV has explicitly documented the ending of earlier effusive phases. The succession of openings described here should therefore not be read as a count of simultaneously active vents. Each source is reported according to the date and status given by INGV-OE.
Voragine remains central to the activity
Although the location of lava emission has changed, Voragine remains central to the monitoring picture. In the 17 August communiqué, INGV located the centroids of volcanic-tremor sources in the Voragine area at about 3,000 metres above sea level. Ash emission was also continuing from the crater.
Volcanic tremor increased during the afternoon of 16 August and reached a maximum at around 17:40 UTC. It subsequently decreased slightly with weak oscillations, but remained within the high-value range through the morning of 17 August. Infrasound had varied between low and medium levels since the previous afternoon, with most events generated by Voragine and a smaller contribution from the Northeast Crater.
Small deflationary changes, but no significant GNSS shift
The 17 August update also reported small changes in the tilt network compatible with an ongoing deflationary process. Most tilt signals showed variations of around 0.5 microradians. A larger change was recorded at the Cratere del Piano station, which had accumulated approximately 2 microradians from 16:30 UTC on 16 August.
High-frequency GNSS data showed no significant variations outside measurement uncertainty at the time of the communiqué. INGV did not state how long the new vent would remain active or where its lava flow would ultimately stop, so this article does not infer either outcome.
Why Valle del Bove keeps appearing in the updates
Valle del Bove is the large depression on Etna's eastern flank. During the current sequence, INGV has repeatedly described lava developing in the Valle del Leone and Valle del Bove sectors. The latest 17 August effusive opening is itself within Valle del Bove.
The important feature of the present sequence is therefore not simply a growing number of vent openings. It is the changing location and elevation of effusive activity, alongside persistent summit activity at Voragine. Field surveys, surveillance cameras and Etna's multiparametric monitoring network are being used by INGV-OE to document those changes as they happen.
What happens next?
INGV-OE said further updates would be communicated promptly, and field surveys were underway on the morning of 17 August. Until further observations are published, the confirmed picture is limited to what INGV has reported: a new lava-producing vent at 2,200–2,350 m, continuing Voragine ash emission towards the south-east, high volcanic tremor centred in the Voragine area, variable infrasound, small tilt changes compatible with deflation, and no significant high-frequency GNSS variation outside measurement uncertainty.
Etna is clearly in an evolving eruptive phase, but the monitoring data are observations rather than a timetable for what comes next. New vents and changes in lava supply can be documented as they occur; they do not provide certainty about where or when another opening may happen.