The number of VLP seismic events (standard values 5-12) is medium, 8.4 events/hour.

The amplitude of seismic tremor is medium.

The infrasonic activity is medium. The acoustic pressure of explosions is low, 0.31 bar (standard values <1 bar). The amplitude of puffing is low, ~30 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 low: 4.35 MW (12:48 UTC yesterday).

Rockfall activity is high. The number of rockfalls is 15 per day.

SO₂ flux in the NE sector of the crater terrace is low, 66 t/d

CO₂ flux based on the C/S of 10.69 mesured at 03:20 UTC on 2025/09/11 is medium, 641 t/d

Indice di Attività Vulcanica: medium

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

In the last 24h, Stromboli volcano showed a MEDIUM degassing activity (puffing/spattering with values of about 30 mbar) located at SW sector, associated to explosions with MEDIUM acoustic pressures (max. 0.31 bar). The volcanic tremor shows MEDIUM values. The number of VLP events is MEDIUM (8.4 events/hour). MODIS and VIIRS satellite images show LOW thermal anomalies (max 4.35 MW). SO2 flux is LOW (66 t/d). CO2 flux, evaluatd using the C/S ratio of 10.69, measured on 11/09/2025 at 03:20 UTC, is MEDIUM (641 t/d). The rockfall activity is HIGH, with 15 evens detected in the past 24 hours having LOW seismic energies. The Volcanic Activity Index is MEDIUM.