At 20:01 UTC / 22:01 local, the surveillance network recorded a larger than usual explosive event in the area of the terrace of the Central / Central-South crater of Stromboli.
Analysis of the images indicated that the eruptive activity produced a significant emission of materials which reached heights of over 150 meters at the mouth and which dispersed beyond the crater terrace, affecting the area. of Pizzo and rolling along the Sciara del Fuoco. After the explosive event, no change in explosive activity was recorded.
Seismically, the explosive event at 20:01 UTC is clearly visible at all seismic stations in Stromboli. Regarding the amplitude of the volcanic tremor, a sharp increase was observed from 19:50 UTC with a maximum peak on high values around 20:00 UTC. Currently, the amplitude of the tremor has returned to medium-low values.
Strain signals from GNSS and Stromboli clinometric networks show no significant variation associated with the explosive event
Sources: INGV OE & LGS
The effusive-explosive eruption of Nevados de Chillan continues at unchanged moderate levels.
Two lava flows remain active, L5 and L6, and continue to spread on the NE slopes as visible in the attached image.
A new lava flow formation began to emerge from the summit vent on July 27 and continues to descend on the NE flanks adjacent to the already known L5 / L6 flows.
An almost constant glow visible from the summit crater at night indicates the rise of a batch of magma.
The volcano continues its intermittent moderate explosions from the summit vent. An ash plume rose 1,800 feet (560 m) above the summit and drifted northeast.
Nevados de Chillan - lava flows on 07/27/2021 - flow limits in red / L5 and in green / L6 - new lobe between the two active lava flows - Doc. Sernageomin - one click to enlarge
At 11:33:00 local time on July 31, 2021, an eruption was recorded in the Rincon de la Vieja volcano, the height reached by the column is unknown due to the visibility conditions of the site.
Duration of activity: 2 minutes.
Seismic activity is weaker than yesterday.
Wind direction is unknown at this time.
After this small eruption, the tremor disappeared although, for 2-3 hours, around 12h, a discontinuous tremor of frequency 1-3hz was detected. Geodetic observations show a slight tendency to extend.