Some scientists think we can better understand volcanoes by learning how the gaseous vortexes emerge. By Carolyn Wilke Some volcanoes perform a rather subtle trick: blowing rings of vapor that waft ...

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 ...