These ghostly hoops have been spotted above volcanic events around the world. But how they form has long been a mystery. Mount Etna—located in Catania, Italy—is one of the rare volcanoes that can blow ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. The Camel cigarette sign blowing ...

A group of hikers look at one of the smoke rings 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 ...