Etna volcano (Italy): new eruption with lava fountains from New South East crater on 5 Jan 2012 (paroxysm nr 19)
Thursday Jan 05, 2012 17:59 PM | BY: TP
Lava fountain at dawn during the 1st paroxysm of Etna volcano (photo courtesy: Francesco Pappalardo / www.flickr.com/photos/cicciofarmaco)
Heavy bombardment of glowing scoria and bombs on the fresh snow on the east flank of the New SE cone (photo courtesy: Marco Restivo / www.flickr.com/photos/marcorestivo/)
Strombolian activity started late in the evening of 4 January, but was difficult to observe due to dense cloud cover. The activity increased slowly during the whole night, with more frequent and more powerful single explosions and ejected glowing bombs up to several 100 m height above the crater rim.
At around 4 am , a lava flow started to emerge from the SE fissure cutting through the cone, announcing the slow start of the spectacular paroxysmal phase.
Between 5h30 and 6 am, single strombolian explosions from the summit vent merged into continuous lava fountains up to about 600 m tall, and producing a large ash plume rising several kilometers. This phase was accompanied by the typical steep rise of the harmonic tremor signal as well recorded by INGV.
Only the summit vent seems to have been active in this eruption. In contrast to previous paroxysms, the SE and N fissures did not produce lava fountains.
Strong fountains lasted until 08h05 and the activity dropped sharly and ended at around 8h30.
A very remarkable aspect of this eruption was the generation of small pyroclastic flows and lahars (mud flows). The heavy impacts of incandescent bombs on the snow-covered northern flank and base of the cone generated hydromagmatic steam explosions that turned into mud flows and turbulent mixtures of steam, ash and debris (pyroclastic flows). The latter reached the southern end of the fissure vents of the 2008-2009 eruption, ca. 1 km distance. This is a particular hazard to take into account during such and similar basaltic eruptions on snow-covered volcanoes.
The lava flow produced several branches and took the same path as during the previous eruptions in late 2011, flowing down the steep slope east into the Valle del Bove until an elevation of about 2000 m. A small second lava flow emerged from a breach on the NW crater rim, but only reached the base of the cone.
Links / Sources:
Tuesday, Nov 15, 2011
A new eruptive episode is in progress at the New SE crater of Etna today. Starting this morning, tremor has been rising steeply and at the time of writing, the first strombolian explosions, or even small lava fountains, and perhaps already a small lava flow can be seen emerging from the SE-trending fissure cutting through the cone. All signs point towards that this is going to be the long-awaited 18th paroxysm of the New SE crater in 2011, following the previous one on 23 Oct after 23 days, the longest-so-far interval since July. [more]
Sunday, Oct 23, 2011
Another paroxysmal eruption (the 17th in 2011) is in progress at Etna's New SE crater at the time of writing. The volcanic tremor recorded by INGV has risen sharply to 50 times above background levels, and strong strombolian activity and/or lava fountains, as well as a lava flow into the Valle del Bove are visible from various webcams. ... [more]
Sunday, Oct 09, 2011
Following 10 days of quiet, a new paroxysmal eruption (nr 16 in 2011) took place from the New SE crater of Etna volcano during the afternoon of 8 October 2011. ... [more]
Wednesday, Sep 28, 2011
The 15th paroxysm of Etna's New SE crater occurred in the evening of 28 Sep, a few days earlier than what statistically had been expected (based on thze steady increasing intervals between the past similar events). ... [more]
Monday, Sep 19, 2011
The 14th paroxysm of Etna's New SE crater is in progress at the time of writing. Bad weather conditions hide the eruption, but the seismic signals of INGV Catania show that a major eruptive episode is occurring. Since 9am, volcanic tremor has been gradually increasing to (at the moment) 30+ times background levels, and is still rising. Most likely, lava fountains are being ejected from vents inside the crater and lava flows descending into Valle del Bove if the new episode is similar to the previous ones. ... [more]