Global Volcanism Program | Image GVP-04044
The steep-walled inner crater of Santa Ana volcano is half a kilometer wide and is partially filled by a 250-m-wide greenish crater lake. Fumaroles are located on the crater wall and in the lake, and abundant sulfur deposits are located on the SW wall (upper left). The acidic crater lake has a pH of about 1, and recent bathymetric surveys revealed that the lake was shallow, with a maximum depth of 27 m. Lake temperature in May 2000 increased to 30 degrees Centigrade.
Copyrighted photo by Dick Stoiber, 1966 (Dartmouth College).