"Mount Etna's Spectacular Smoke Rings Light Up Sicilian Sky"
Italy's Mount Etna recently produced perfectly circular volcanic vortex rings, some with a pink hue, a phenomenon first observed in 1724 and now seen at various volcanoes worldwide. The rings are formed by a combination of fast gas release from gas bubbles at the top of the magma conduit and regularity in the shape of the emitting vent, and are composed of roughly 80% water vapor and 20% sulfur dioxide and carbon dioxide. Etna's unique crater shape contributes to the rings' circular nature, and the recent quantities of rings produced were described as "unprecedented" by a Sicilian volcanologist.
