The number of VLP seismic events (standard values 5-12) is high, 15.6 events/hour.

The amplitude of seismic tremor is high.

The infrasonic activity is medium. The acoustic pressure of explosions is medium, 0.7 bar (standard values <1 bar). The amplitude of puffing is high, ~90 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, 2133. The amplitude of thermal transients is low, 3 ºF. Exit velocity of pyroclasts, estimated through thermal camera analysis, is low, 11 m/s.

MODIS thermal anomalies: no thermal anomalies.

Rockfall activity: no rockfalls detected.

SO₂ flux in the NE sector of the crater terrace is medium, 74 t/d

CO₂ flux based on the C/S of 5.97 mesured at 07:20 UTC on 2026/05/19 is low, 278 t/d

Indice di Attività Vulcanica: high

• Seismic (VLP) rate HIGH
• Seismic tremor HIGH
• Puffing HIGH
• Acustic pression of explosions MEDIUM
• Thermal activity MEDIUM
• SO₂ flux MEDIUM
• CO₂ flux LOW
• Rockfall activity LOW

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 HIGH degassing activity (puffing/spattering with values of about 90 mbar). The explosive activity is MEDIUM (max acoustic pressure 0.7 bar). The volcanic tremor shows HIGH values. The number of VLP events shows HIGH values (16 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 NO thermal anomalies. SO2 flux shows MEDIUM values (last: 74 t/d recorded on the 198/05/2026), CO2 flux shows LOW values (last: 278 t/d based on C/S value of 5.97 recorded on the 19/05/2026). The rockfall activity is LOW (zero events detected). The volcanic activity index is HIGH.