Explosive activity at Italian Stromboli volcano intensified on January 5, 2019, especially in its northeastern vents where a new cinder cone is growing.
Seismic signals suggesting fracturing in the summit zone of Stromboli volcano are being recorded since December 24, 2018, when Italian Civil Protection raised the Alert Level from Green to Yellow. This activity was followed by increasing spattering in the crater terrace since December 26 and detection of seven active vents.
A series of strong explosions were observed at the NE vent on January 3. This activity further intensified on the evening of January 5 with several vents all active at once.
"In particular, in the NE cluster of vents where a new cinder cone is growing and continuous lava spattering as well as larger strombolian explosions with plenty of red-hot lava spatter ejected to probably more than 200 m (656 feet)," volcanologist Dr. Tom Pfeiffer reports.
"It is obvious that currently, the magma column inside the conduits stands high, ready perhaps to produce an overflow in the near future," Pfeiffer concludes.
An ordinance issued by the Municipality of Lipari on January 4, 2019, prohibits access to Stromboli above 400 m (1 312 feet) above sea level.
The Mayor of Lipari indicates that the "high" level of activity of the volcano at the moment motivates this decision. Authorized guides - only in the context of monitoring operations - are not affected by the prohibition, Claude Grandpey reports.
According to Stromboli Daily Report published by the Laboratorio Geofisica Sperimentale (LGS) at 07:39 UTC on January 6, the number of VLP seismic events (standard values 5-12) is high, 16.0 events/hour (16.2 yesterday).
The amplitude of VLP events is medium.
The amplitude of seismic tremor is high.
The infrasonic activity is high. The acoustic pressure of explosions is high, 3.19 bar (standard values <1 bar). The amplitude of puffing is very high, ~230 mbar.
Tiltmeters analysis shows no significant deformation. Thermal activity of explosive events is high. The number of thermal transients in the NE sector of the crater(standard = 100) is high, 187. The amplitude of thermal transients is low, <20 ºF. Exit velocity of pyroclasts, estimated through thermal camera analysis, is medium, 25 m/s.
SO2 flux in the NE sector of the crater terrace is 77 t/d.
HQ Stromboli webcam is here.
Featured image: Stromboli erupting on January 6, 2018. Credit: INGV Catania