Europe's most active volcano, Mount Etna, is blowing scores of ethereal"vortex rings" every day from a single vent located in one of its most active craters.
Vortex rings are made from a mix of smoke, steam and other gases released from volcanic vents at high speeds. They can remain airborne for several minutes before eventually disappearing. Mount Etna produces more vortex rings than any other volcano in the world, Behncke wrote. The Sicilian volcano spits out the gaseous loops most years, but the number of the rings varies every year. In 2000, the volcano released around 5,000 — the most on record — and the current rate is similar to that period, he added.