Mysterious Vortex Rings Emerge from Europe's Active Volcano

Mount Etna, Europe's most active volcano, is producing numerous "vortex rings" from a single vent in its Bocca Nuova crater. These rings, made of smoke, steam, and gases, can remain airborne for several minutes. The volcano has been releasing these rings for about a week, with no signs of stopping. Mount Etna produces more vortex rings than any other volcano, and the secret lies in the shape of the conduit below the vent. Recent activity also includes the opening of a new vent and minor eruptions, but experts say a major eruption is not imminent.