Global Volcanism Program | Image GVP-00527
A 300-m-wide crater near the summit of Sibayak volcano contains a small turquoise-colored crater lake and areas of extensive hydrothermal alteration and sulfur mineralization. Plumes rise above active fumaroles at several locations along the far crater wall.
Photo by Tom Casadevall, 1987 (U.S. Geological Survey).
This image is made available as a Public Domain Work, but proper attribution is appreciated.