“The rings look just about just like the ‘smoke rings’ produced by an in a position smoker,” Boris Behncke, a volcanologist on the Italian Nationwide Institute of Geophysics and Volcanology’s Etna observatory, mentioned in an e mail Monday.
He defined that the rings had been fashioned by magma — molten rock with gasoline — effervescent beneath a cylindrical vent that opened right into a crater that fashioned on Etna’s floor final week.
“Think about a really slim, cylindrical conduit, inside which, at a sure depth, there’s magma,” Behncke mentioned. “On occasion, a bubble kinds on the floor of the magma, bursts, and sends a slug of gasoline at excessive velocity by means of that conduit.”
As pulses of gasoline squeeze up the slim, round vent, they tackle its ring-like form — forming the puffs. “You gained’t get rings from a extra irregular form of the vent,” he mentioned.
The gasoline rings are composed of about 80 p.c water vapor, with the remaining 20 p.c principally manufactured from sulfur dioxide and carbon dioxide, he mentioned. It’s the water vapor that offers the rings their white hue, making them resemble smoke rings.
Mount Etna first erupted about 500,000 years in the past. Since then, it has often dazzled vacationers and Sicilians alike with its lava flows — together with a molten fountain that reached heights of near a mile in 2015.
Its volcanic exercise has additionally brought on critical disruption and harm, emitting hazardous ash clouds that compelled the close by airport to shut and encased villages in ash. In 1979, a fluke crater explosion killed 9 vacationers — though deaths are unusual. In a Seventeenth-century explosion, Etna buried the city of Nicolosi, destroyed a lot of the town of Catania and fired molten rock into the ocean 18 miles away.
In keeping with Behncke, the rings will not be notably uncommon phenomena. Etna is “probably the most prolific volcano on this planet when it comes to vapor rings,” he mentioned.