Update on the eruptive activity of Etna, 3 January 2011

Strombolian activity within the pit crater located on the lower east flank of the Southeast Crater cone, photographed from Trecastagni shortly after midnight on 3 January 2011. The inner walls of the pit are brightly illuminated by the magmatic activity taking place in the western portion fo the pit (the incandescent jet seen at left). Photo by Boris Behncke, INGV-CT

On the late afternoon of 2 January 2011, a strong glow appeared within the pit crater that is located on the lower eastern slope of the Southeast Crater cone, and during the following hours this evolved into vigorous, though modest Strombolian activity. This activity continued through the early morning, and decreased markedly after 06:00 local time (= GMT+2). The episode was accompanied by a significant increase in the volcanic tremor amplitude, which peaed around midnight and during the forenoon decreased to background levels. Between 23:00 on 2 January and 02:00 on the next day, the activity consisted of frequent Strombolian explosions (about 1-3 per minute), which launched coarse-grained incandescent material up to a few tens of meters above the rim of the pit. On a few occasions, incandescent bombs fell outside the pit's rim, mainly to the south and to the east. No outflow of lava occurred, and the event produced negligible quantities of volcanic ash.

Video frame captured from footage recorded by the Schiena dell'Asino of the INGV-CT at 17:28 local time on 29 December 2010. A small jet of incandescent material - presumably hot gas - is seen rising from the pit crater on the eastern flank of the Southeast Crater cone, which itself is in the center of the image.

The episode of 2-3 January has been preceded by several days of repeated emissions of incandescent material, probably hot gas, from the same pit crater, and a dull glow was periodically visible during the night of 1-2 January. It is furthermore possible that on the afternoon of 23 December 2010 a similar episode of Strombolian activity had occurred at the same pit, during a period of strongly increased volcanic tremor amplitude. However, bad weather precluded observations of the summit area; only in the video footage recorded by the Schiena dell'Asino monitoring camera a bright glow is intermittently visible between 16:00 and 16:05 of 23 December, located in correspondence with the pit crater.