Same day, same place as previous picture. This white, brilliant steam ring kept its circular shape for nearly 15 minutes, reaching an altitude of several kilometers. It was carried by a strong wind in an eastern direction to the sea. When the weather conditions are right, the vent of the Bocca Nuova produces nicely-shaped rings every 10 minutes, mostly 20 to 50 m ( 60 to 150 feet) across. Some of these rings attain a diameter of 200 m (about 600 feet) maintaining their shape for 10 to 15 minutes before breaking up.
[© Thorsten BOECKEL - photo used with permission (more images of volcanoes and smoke rings can be found on Thorsten's personal site at www.tboeckel.de)]