Fifth consecutive paroxysm on Etna this night:
Around 8:50 p.m., a weak Strombolian activity occurred at the level of the SE crater. The average amplitude of the volcanic tremor gradually increases while remaining at the current state at the average level.
At 9:10 p.m., the INGV recorded an increase in the frequency and intensity of Strombolian activity at the south-eastern crater, with the launch of products in abundance outside the rim of the crater. The mean amplitude of the volcanic tremor shows a further sudden increase and is in the high level.
The source of the tremor shows a gradual displacement of the Bocca Nuova towards the SE crater, at a depth of 2500 m above sea level.
The infrasonic activity is dramatically increased with a high rate of occurrence of infrasonic transients. These are located in correspondence with the SE crater.
At 22:05 GMT, the eruptive activity further intensified with jets of lava 300m high above the SE crater. The average amplitude of the volcanic tremor shows high values with an increasing trend. The source of the tremor is located under the SE crater, in a depth range of 2800 to 2900 m above sea level.
Etna - towards the 5th paroxysm - video sample Local team / via Szabolcs Harangi - one click to enlarge
At 22:27 UTC, a second vent was activated in the SE crater producing lava fountain activity. At 22:28 UTC, there was an overflow towards Valle del Bove. The lava front is currently at an altitude of about 3000 m.
Activity around 23:30 GMT intensified further, generating lava jets up to 1,000 meters high above the SE crater. This activity produced an eruptive column which rose several kilometers from the summit of Etna. At the same time, the activity started another lava overflow from the mouth of the saddle, feeding a lava flow directed towards the southwest.
Etna - video of the lava fountains of the 5th paroxysm - by Turi Caggegi 23.02.2021
Etna - 23.02.2021 / 01h local - subplinal eruptive column seen from Tremestieri Etneo - photo Boris Behncke
As of 00:15 GMT, there was a sudden decrease in the lava fountain. The effusive activity of the two lava flows continues; they overlap with the streams of the previous episodes. The explosive activity at the summit craters also continues.
The average amplitude of the volcanic tremor, after reaching its maximum value at 23:50 UTC, suffered a sudden decrease, while remaining in the upper range. The source of the tremor is located in the area of the SE crater, at a depth of 2700-2800 m above sea level.
From 03:50 GMT, there is an increase in the frequency and intensity of Strombolian activity, accompanied by the emission of ash at the SE crater, with the launch of products abundantly outside the rim of the crater until 'at a height of about 300 m. At the same time, two small lava flows formed, one towards the Valle del Bove and the other towards the southwest.
Regarding the amplitude of the volcanic tremor, after reaching average values, after the end of the previously communicated fountain activity, from 3h50 GMT, it showed a sudden increase moving upwards. The location of the source remains below the SE crater at an altitude of about 2,800 meters above sea level.
Source: INGV OE
During the past two weeks at the Laguna del Maule Volcanic Complex, the Southern Andes Volcanological Observatory (OVDAS) has detected 533 volcano-tectonic (VT) seismic events, associated with a rock fracture within the volcanic system, and rates deformation of 2.3 cm / month, higher than the average since 2012.
Therefore, SERNAGEOMIN decided to change the technical alert from green to YELLOW, which was reported in the volcanic activity report for the last fortnight.
Moreover, it was observed that the type of VT events were persistent in time and increased in size.
Its establishments are concentrated in the Las Nieblas sector, south of the lagoon, a place where carbon dioxide anomalies have been detected since 2019.
Finally, a hazard zoning with a radius of 2 km is reported around the site of the CO2 anomaly, in which it is recommended not to access (map attached).
Source: SERNAGEOMIN RAV.