Volcanoes
Under particular conditions, some volcanic vents can produce large visible smoke rings. It is a rare phenomenon but several volcanoes have been observed emitting massive vortex rings of steam and gas:
- Mount Etna, Italy (Sicily)
- Stromboli, Italy (Aeolian Islands)
- Eyjafjallajökull, Iceland
- Hekla, Iceland
- Tungurahua, Ecuador
- Pacaya, Guatemala
- Mount Redoubt, USA (Alaska)
- Aso-san, Japan (Kyushu)
- This list is incomplete; you can help by expanding it.
Read more about this topic: Smoke Ring