For just over a week, Mt. Etna, one of Europe’s most active volcanoes, has been spewing circular, mostly white smoke rings into the skies over Sicily.
It’s not the first time Mt. Etna has enchanted onlookers with its puffing (it’s been dubbed the Gandalf of volcanoes, after the pipe-puffing wizard in “Lord of the Rings.”) But experts there say this month Etna “has broken all previous records” with the frequency of the rings, according to Boris Behncke, a volcanologist at the National Institute of Geophysics and Volcanology of Catania, who posted about the phenomenon on Facebook.
The rings, known as volcanic vortex rings, appeared earlier this month after a small vent opened on the northwest border of the Southeast crater. The phenomenon occurs when enough pressure builds up so that magma inside the crater propels condensed gases, predominantly water vapor, through the vent.
In this case, the vent is perfectly circular, making for particularly perfect rings. “It is bellissimo,” said Simona Scollo, another volcanologist at the INGV Etna Observatory in Catania, using the Italian word for beautiful. Ms. Scollo copublished a study on the dynamics of volcanic vortex rings last year in the journal Scientific Reports.
But, she said, the activity does not mean that Mt. Etna is going to erupt in a particularly spectacular way. “No, no, no,” she said.
During a telephone interview Tuesday, she said that the mechanism for the smoke rings was similar to how dolphins blow bubble rings. “They compress the water in their mouths, and using their tongue they push it out of their mouths and create such a pressure that it forms a ring,” she said.
