The number of VLP seismic events (standard values 5-12) is high, 14 events/hour.

The amplitude of seismic tremor is high.

The infrasonic activity is medium. The acoustic pressure of explosions is medium, 0.8 bar (standard values <1 bar). The amplitude of puffing is medium, ~40 mbar.

Tiltmeters analysis does not show any significant deformation of the volcano edifice

Thermal activity of explosive events is medium. The number of thermal transients in the NE sector of the crater (standard = 100) is high, 638. The amplitude of thermal transients is low, 2 ºF. Exit velocity of pyroclasts, estimated through thermal camera analysis, is low, 15 m/s.

MODIS thermal anomalies are low: 3 MW (01:42 UTC yesterday).

Rockfall activity is medium. The number of rockfalls is 6 per day.

SO₂ flux in the NE sector of the crater terrace is medium, 89 t/d

CO₂ flux based on the C/S is not available

Indice di Attività Vulcanica: high

• Seismic (VLP) rate HIGH
• Seismic tremor HIGH
• Puffing MEDIUM
• Acustic pression of explosions MEDIUM
• Thermal activity MEDIUM
• SO₂ flux MEDIUM
• CO₂ flux not available
• Rockfall activity MEDIUM

The volcanic activity is generally characterized by strombolian explosions and degassing (puffing/spattering) located at NE and SW crater sectors. In the last 24h, the Stromboli volcano showed a MEDIUM degassing activity (puffing/spattering with values of about 40 mbar). The explosive activity is MEDIUM (max acoustic pressure 0.8 bar). The volcanic tremor shows HIGH values. The number of VLP events shows HIGH values (14 events/hour). The number of explosions (thermal transients) are HIGH, with a LOW thermal amplitude and LOW exit velocity of pyroclasts. MODIS/VIIRS thermal data shows LOW thermal anomalies (Max 3 MW). SO2 flux shows MEDIUM values (last: 89 t/d recorded on the 17/05/2026), CO2 flux shows no new data (last: 474 t/d based on C/S value of 4.85 recorded on the 16/05/2026). The rockfall activity is MEDIUM (n.6 events detected with MEDIUM pseudo-volumes associated). The volcanic activity index is HIGH.