English: NASA�s Terra satellite passed over Sicily at 9:45 UTC (10:45 a.m. local time) on December 4, 2015 � just in time for the Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard to capture a spectacular true-color image of a paroxysm from Mt. Etna�s Voragine crater. The large ash cloud was rising straight up from Mt. Etna, creating a pale gray oval that obscured the volcano from view.

Mt. Etna stirred from a two-year respite on December 2, when the Voragine crater began to send fountains of lava and jets of hot material into the air. This short but violent and spectacular phase, known as a paroxysm, lasted less than an hour. At the peak sustained lava fountains reached over 1 km (3,280 ft.) above the crater while jets of hot material and ash reached 3 km (9,843 ft.) above the summit. Ash fallout reached several villages located northeast of the volcano. This paroxysm was considered the most violent of Mt. Etna�s eruptions in the last two decades.

A second, equally spectacular, paroxysm occurred the morning of December 4. Tremor started to rise steeply after 8:40 a.m. local time (7:40 UTC), followed by intense fountaining of lava. An ash column, captured from above in this image, rose to 9 to 11 km (29,500 � 36,089 ft) altitude, then drifted eastwards. The morning paroxysm decreased sharply after 11:15 a.m. local time (10:45 UTC). Mt. Etna�s Voragine crater continued its activity with a third paroxysm shortly before midnight on December 4. The lava fountains appeared as intense as the initial paroxysm with robust ash emission. In addition, the New SE crater also began to lob incandescent materials into the air, although not as spectacularly as Voragine. The airport of Catania was closed due to the heavy ash plumes.

The volcano continued lower-level strombolian activity through the night and much of the next day, with a fourth spectacular paroxysm at Voragine on December 5. A new pit crater appeared on the New SE crater and produced heavy strombolian activity (short-lived, explosive outbursts that eject lava and ash). Significant lava flow was seen from the New SE crater on December 6-7. Most activity had decreased by December 8.

On December 9, activity at Voragine and the New SE crater had seemed to calm, but the NE crater began to emit near-continuous ash venting. The NE crater calmed by the next day, and by December 11 the consensus seemed to be that the volcano was calm, with all eruptive activity ceased. However, the NE crater began to emit ash again on December 12. Whether or not the volcano will become quiescent or renew its current eruptive phase will be answered over the coming days.

Mt. Etna is Europe�s most active volcano with a long history (more than 2000 years) of spectacular and violent eruptions. According to the Volcano Discovery website, Mt. Etna is considered, after Kilauea in Hawaii, the second most active (i.e. productive) volcano on Earth.