Global Volcanism Program | Image GVP-01044
The active Kawah Mas crater contains numerous high-temperature fumarolic vents, many surrounded by deposits of sulfur. The fumarole temperatures are monitored by scientists from the Volcanological Survey of Indonesia. Phreatic explosions have occurred during historical time from vents near Kawah Mas.
Photo by Lee Siebert, 1995 (Smithsonian Institution).