Global Volcanism Program | Image GVP-10162
Sequences of phreatomagmatic tephra layers are exposed in the southern and western crater walls of Santa Ana. The hydrothermally altered area to the lower right is the inner crater, which contains an acidic lake not visible in this photo. Four crater walls can be seen in this photo; the two outer walls appear in the center on and below the horizon, beyond the flat rim of the inner crater.
Photo by Lee Siebert, 2002 (Smithsonian Institution).
This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.