After four weeks of moderate activity at its summit craters, Etna has unleashed a new paroxysmal eruptive episode from its Southeast Crater on the evening of January 18, 2021. The Aviation Color Code was raised to Red at 20:21 UTC and lowered back to Orange at 05:46 UTC on January 19. The last time Etna's Aviation Color Code was raised to Red was on January 6, 2021.
Volcanic and infrasonic tremors increased at 19:00 UTC on January 18, followed by an eruption at 19:15 UTC, with intense Strombolian activity and a new lava overflow from the Southeast Crater. The front headed toward Valle del Bove and reached a height of about 2 900 m (9 500 feet).
Intense Strombolian activity suddenly evolved into a weak lava fountain reaching maximum intensity at 20:30 UTC.
Eruption at Etna volcano on January 18, 2021. Credit: INGV-OE
This activity generated a volcanic cloud that dispersed to the East-Southeast and formed a volcanic ash depot on the eastern flanks of the volcano.
Ashfall was reported in the village of Fleri. In addition, the eruption forced temporary closure of two sectors at Catania Airport.
A second overflow started at 20:46 UTC.
Explosive activity decreased significantly starting at around 21:00 UTC.
After four weeks of moderate activity at its summit craters, #Etna has unleashed a new paroxysmal eruptive episode from its Southeast Crater on the evening of 18 January 2021 pic.twitter.com/GrQwk9P4Va— Boris Behncke (@etnaboris) January 18, 2021
L'attività eruttiva in corso all'#Etna è ben visibile anche dalla famosa baia di Naxos, vicino Taormina.— Il Mondo dei Terremoti (@mondoterremoti) January 18, 2021
La colata lavica è attualmente a 2.900 metri di altitudine e si dirige verso la Valle del Bove.
Si nota dalla foto anche un pennacchio di cenere.
Foto: Carmine Quattropani. pic.twitter.com/0LybbwOTB4
As far as effusive activity is concerned, Etna Volcano Observatory (INGV-OE) video surveillance cameras showed two distinct lava flows: one heading east, inside Valle del Bove, and the other northward.
A rapid decrease in volcanic tremor and the infrasonic signal has been recorded starting at 21:00 UTC.
Around 21:30 UTC both signals reached the levels that preceded eruptive activity.
Deformation data showed no significant changes.
INGV-OE lowered the Aviation Color Code back to Orange at 05:46 UTC on January 19.
Mount Etna, towering above Catania, Sicily's second-largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy.
The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km (5.1 x 6.2 miles) horseshoe-shaped caldera open to the east.
Two styles of eruptive activity typically occur at Etna. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more of the three prominent summit craters, the Central Crater, NE Crater, and SE Crater (the latter formed in 1978).
Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by strombolian eruptions at the upper end).
Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank. (GVP)
Featured image credit: INGV-OE