Dark smoke surges from the crater of Mount Etna in Catania, Italy, Dec. 14, 2021. (Photo/Agencies)
Mount Etna, Europe's most active volcano, has erupted many times in 2021.
Dark smoke surges from the crater of Mount Etna in Catania, Italy, Dec. 14, 2021. (Photo/Agencies)
Dark smoke surges from the crater of Mount Etna in Catania, Italy, Dec. 14, 2021. (Photo/Agencies)