A sharp rise in volcanic tremors signaled the start of a new Strombolian eruption at Mount Etna, Italy, early on June 2, 2025. Ash and sulfur dioxide (SO₂) clouds drifted to the southwest. The Aviation Color Code was elevated to Red at 03:32 UTC and lowered to Orange at 06:39 UTC.
Intense Strombolian activity was observed at Mount Etna’s Southeast Crater, Italy, during the early UTC hours of Monday, June 2.
Volcanic tremor amplitude began gradually increasing around 22:00 UTC on June 1, reaching elevated levels by approximately 00:50 UTC on June 2.
The tremor’s centroid was located near the Southeast Crater at an elevation of about 2.8 km (1.7 miles) above sea level.
Infrasonic activity began to slightly increase around 00:30 UTC, concentrated in the summit crater area. A sudden shift in monitoring parameters was detected at 00:39 UTC on June 2, followed by visible Strombolian eruptions at the Southeast Crater around 01:50 UTC.
The National Institute of Geophysics and Volcanology, Etna Observatory (INGV-OE), raised the Aviation Color Code from Green to Yellow at 01:23 UTC, then to Orange at 02:02 UTC, and finally to Red at 03:32 UTC, in response to visible explosive activity and rising seismic amplitude. As the eruption weakened, the alert level was lowered back to Orange at 06:39 UTC.
While early satellite images did not detect a volcanic ash cloud, a plume primarily consisting of water vapor and sulfur dioxide (SO₂) was observed drifting southwest. By 06:59 UTC, the Toulouse VAAC reported a weak ash plume reaching 5.5 km (18,000 feet), moving southwest at about 20 km/h (12 mph).
Deformation data from GNSS, clinometric, and strainmeter networks showed no significant changes during the event. The volcanic activity remained confined to Etna’s summit craters, with no reports of ashfall affecting nearby communities.
