New ash emissions from NE crater
Update Sat 12 Dec 16:19The NE crater started again to produce puffs of ash, generating small plumes drifting southwest.
Update Fri 11 Dec 08:49The volcano is at the moment calm. During Wednesday, the initially strong ash-venting activity from the NE crater decreased and stopped yesterday.
Earthquake activity at the NE side also progressively decreased.
Update Wed 09 Dec 13:45
Ash emissions from NE crater
Depth vs time of recent earthquakes under Etna
According to INGV scientists, the volcano had experienced mild inflation prior to the paroxysm last weekend, and this inflation disappeared. The earthquake swarm on the NE side, still ongoing, but also weakening, is thought to be the cause of compression stress, not extension. In that case, the scenario of a new flank eruption on the NE rift in a near future is much less likely.
Strong ash emissions from NE crater
Update Wed 09 Dec 08:04Another of the summit vents seems to be becoming protagonist in the current eruptive phase: the NE crater has been producing near-continous small to moderate ash emissions throughout the night and the morning. Incandescence was occasionally seen at the base of the plumes as well, suggesting strombolian activity.
The other vents, in particular Voragine and New SE crater, have been calm.
The NE crater, formed in 1911, had not had much significant activity since 1995-1996 when it produced a series of spectacular paroxysms with associated lava flows.
Shallow earthquakes under Pernicana fault could herald new flank eruption?
Update Tue 08 Dec 19:35
Over the morning, surface activity at Etna's New Southeast Crater strongly decreased, and the lava flow seems no longer be active now. Tremor has dropped as well, but ash emissions and occasional explosions continue from several of the summit craters, including the Northeast.
This morning's earthquakes at the Pernicana fault of Etna
Explosion from NE crater
Etna's lava flow last night (photo: Alessandro Lo Piccolo / facebook)
Current tremor signal (ESLN station / INGV Catania)
Another significant sign of unrest appeared this morning in the form of small earthquakes, up to magnitude 3.8 and some felt by locals, at shallow depths on the Pernicana fault in the NE sector of the volcano.
The most significant quakes (out of 46 total recorded until 12:45 local time) were at 10:28 (M3.8), at 10:32 (M2.9), at 10:36 (M2.4) and 11:53 (M3.2) at depths between 2-4 km.
Small fractures approximately 2-4 cm wide were noticed on the road surface of the Mareneve road, above an altitude of 1450 m above sea level.
In addition, at the same time, two earthquakes were recorded under the loweer northern slope in the Solicchiata area at 00:21 (M2.6) and at 10:36 local time (M2.4) at depths of between 7 and 14 km.
The Pernicana fault has in the past often acted as the "opener" of the NE rift zone, prone to flank eruptions (last so in Oct 2002). Could this time be similar, could the earthquakes be a precursor of another flank eruption ? Nobody can be sure, but for sure, these signs are at least a bit worrying.
New lava flow into Valle del Bove
Update Tue 08 Dec 09:09
Lava flow from Etna's New SE crater this morning
Activity today has decreased, but lava effusion seems to continue. This is likely only a pause in what is certainly one of Etna's most interesting eruptive phases in recent years.
Notice: We offer a volcano special tour to Etna from 11-14 Dec!
Lava flow from New SE crater
Update Sun 06 Dec 15:12The activity at the New SE crater has been continuous all day and is still gradually increasing. A low lava fountain feeds a lava flow from the new pit crater. This flow occasionally generates small pyroclastic flows as parts of its front collapse on the steep slope.
Some pictures taken around noon:
Strombolian activity from New SE crater
Update Sun 06 Dec 09:24
Ash plume from Etna's New SE crater (r)
Activity from New SE crater
While explosions continued from Voragine crater and tremor levels remain high, it seems that since a few hours ago, most magma has now been using another vent: the new pit crater on the upper flank of the New SE crater.
It already has had intermittent activity throughout the current eruption, but this morning started to produce intense strombolian activity and dense ash plumes.
The situation remains highly interesting.