The number of VLP seismic events (standard values 5-12) is high, 17.8 events/hour.

The amplitude of seismic tremor is medium.

The infrasonic activity is medium. The acoustic pressure of explosions is high, 1.6 bar (standard values <1 bar). The amplitude of puffing is medium, ~47 mbar.

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

Thermal activity of explosive events is not available. The number of thermal transients in the NE sector of the crater(standard = 100) is not available. The amplitude of thermal transients is not available. Exit velocity of pyroclasts, estimated through thermal camera analysis, is not available.

MODIS thermal anomalies are high: 268 MW (08:10 UTC yesterday).

Rockfall activity: no rockfalls detected.

SO₂ flux in the NE sector of the crater terrace is medium, 103 t/d

CO₂ flux based on the C/S of 12.73 mesured at 03:20 UTC on 2026/04/20 is high, 1360 t/d

Indice di Attività Vulcanica: medium

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

The volcanic activity is generally characterized by strombolian explosions located at the NE crater sector and degassing (puffing/spattering) located at NE and SW crater sectors. In the last 24h, Stromboli volcano showed MEDIUM degassing activity (puffing/spattering with values of about 47 mbar). The explosive activity is HIGH (max acoustic pressure 1.6 bar). The volcanic tremor shows generally MEDIUM values. The number of VLP events shows HIGH values (17.8 events/hour). MODIS/VIIRS thermal data show HIGH thermal anomalies (268 MW) in agreement with the lava overflow from 18/04/2026. SO2 flux shows MEDIUM values (103 t/d recorded on 19/04/2026), The CO2 flux, estimated using a C/S ratio of 12.73 measured on 20/04/2026 at 03:20 UTC, shows HIGH values (1360 t/d). The rockfall activity is LOW (no events detected in the last 24h). The volcanic activity index is MEDIUM.