Global Volcanism Program | Image GVP-02751
A geologist examines a fumarole surrounded by sulfur mineralization at Sherman Crater in 1981. Greatly increased thermal emission beginning in 1975 melted glacial ice in Sherman Crater and created many new fumaroles. Plumes are occasionally visible from the Puget lowlands.
Photo by Bill Chadwick, 1981 (U.S. Geological Survey).