A strange phenomenon has been observed in the sky over Sicily. Etna, the highest active volcano in Europe, has formed magnificent circles in the sky, just like what smokers of shisha or puff can do. Contrary to what one might think, it is not smoke but volcanic gases.
The phenomenon, quite rare, occurs when gas bubbles rise along the magma chamber along conduits and explode. “At first glance, the process seems relatively similar to that used by a smoker,” notes Futura Science. The vapor emitted by the volcano or exhaled by a person is slowed down on contact with the walls of the volcanic conduit or the mouth. The gas then begins to rotate on itself, forming a ring which will rise into the air. »
Etna.🌋
Design of the year 04/06/2024
No, it's fake.
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— Sabrina F. (@itsmeback_) April 6, 2024
The conditions necessary for the volcano to form circles
If the smoker is capable of making circles at will, this is not the case with the volcano. “The formation of these steam rings is closely linked to the way in which the magma will degas,” explains a study published in Scientific Reports.
Small bubbles that form in magma and collect in pockets in volcanic conduits explode when the pressure becomes too high and propel the gas at high speeds. To form circles, the gas must escape from a circular or slightly crushed area, without too many irregularities, which would destroy the gas ring during its passage, and in a not too large quantity (between 21 and 42 m3).
#Etna's Southeast Crater continues emitting countless graceful vapor rings ("volcanic vortex rings"), a phenomenon never seen like this before. Someone said "maybe because we receive so much bad news lately, Etna has decided to do something simply beautiful". April 5, 2024 pic.twitter.com/zVxsKzX99K
— Boris Behncke (@etnaboris) April 5, 2024
“Volcanic vortex rings” have already been observed in the sky above the volcano peaking at 3,324 m above sea level. Volcanologist Boris Behncke, who works at the National Institute of Geophysics and Volcanology (INGV) in Catania, points out that since April 2, Etna has been breaking all records by emitting “unprecedented quantities of gas rings”.