Etna volcano update: Powerful lava fountains generate massive ash plume over Sicily
Fr, 12. Mär 2021, 15:3215:32 PM | VON: T
Eruption column and plume from Etna's paroxysm today reaching approx. 10 km altitude (image: Fernando Famiani / EtNativo / facebook)
Thermal view of the lava fountain from Montagnola (image: INGV webcam)
The 12th paroxysm from Etna's New SE crater in less than a month occurred during the morning today, as had been expected since the early hours when activity started to pick up. It was particularly powerful and rather long-lasting, marking the 12th such event in a row.
Volcanic tremor signal (image: INGV Catania)
After a rather slow start, lava fountaining began around 8am local time, and increased until reaching a peak phase during 9:30-10:40 am. During the peak of the eruption, the ash and steam column rose up to approx. 10 km altitude and drifted east, causing heavy lapilli and ash fall in places on the eastern sector of the volcano including Milo, Giarre and others.
The volcano observatory in Catania (INGV) gives a detailed summary of the event in this post on their blog, translated as follows:
"In the early hours of 12 March 2021, Etna, almost as precise as a clock, registered the start of new Strombolian activity at the New Southeast Crater (NSEC) of modest intensity, while at the same time the intracrateric explosive activity continued at the Voragine, Bocca Nuova and the North East Crater vents. Almost immediately, the average amplitude of the volcanic tremor showed a marked increase reaching high values, while the sources of the tremor moved below the New SE crater to a depth of about 2.5 km. It was clear that this was the prelude to a new paroxysmal episode, the twelfth in just under a month.
"From 6:30 am (local time), strombolian activity at the NSEC increased in intensity and frequency, producing a first significant eruption plume. A further increase in Strombolian activity began at 7:54 am, accompanied by a lava overflow from the eastern area of the NSEC, which expanded towards the Valle del Bove.
"At 8:41 am, the Strombolian activity merged to a lava fountains, and caused the eruption column to grow to approx. 3 km height, reaching 6000 m of altitude and drifting by the westerly winds towards the east. The lava flow continued to expand towards the Valle del Bove, reaching an altitude of about 2800 m asl.
"At 9:39, the eruptive cloud produced by the ongoing activity reached an altitude of about 8500 meters, dispersing to the east. The ash fallout affected the towns of Fornazzo and Giarre and subsequently also those of Milo, Santa Venerina and Torre Archirafi. The front of the lava flow that expanded in Valle del Bove reached an altitude of about 2000 m asl.
"The lava fountain activity ceased at 10:50 am; weak Strombolian activity and ash emissions at the Southeast crater continued for some time. At 11:15 the activity was essentially over. The main lava flow continued to be moderately fed, with a lava front down to about 1700 m asl. A second lava flow was also observed which spread south-east on the western side of the Valle del Bove up to an altitude of about 3000 m asl and also appears to be no longer fed and cooling.
"The average amplitude of the volcanic tremor decreased rapidly, remaining at a medium-low level. The analysis of soil deformations, in particular of the clinometric data which are the most sensitive, showed, also in this case, small variations in different stations, with maximum values (in any case less than 3 microradians) recorded by the Cratere del Piano station (ECP). The data of the GNSS network, on the other hand, does not show significant variations.
"The twelfth paroxysm of the sequence that began in February 2021 occurred approximately 54 hours after the previous one.
Image credit: Fernando Famiani / EtNativeo / facebook
Fr, 12. Mär 2021, 13:15