Furnas volcano, at the eastern end of Sao Miguel Island, contains two nested calderas. The southern rim of the younger 6-km-wide caldera is seen here from the north, with Furnas Lake on the right foreground. At least 10 trachytic pumice layers, all erupted during the past 5,000 years, post-date the caldera. The dome with the semi-circle of trees in the center behind the lake is the site of the most recent eruption at Furnas, a sub-Plinian eruption in 1630 CE.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Keywords: caldera

Furnas