Global Volcanism Program | Image GVP-02672
Volcanologist Bob Symonds takes gas samples from a sulfur-encrusted fumarole at the summit of Augustine during a quiescent period of the 1986 eruption. Fumarole condensates had a pH of between 0 and 0.5. The maximum measured gas temperatures were 625-645°C.
Photo by Lee Siebert, 1986 (Smithsonian Institution).