Global Volcanism Program | Image GVP-10160
Several nested craters are found at the summit of Santa Ana volcano. Steam rises from fumaroles on the steep-sided NE wall of an inner crater, which cuts the flat-bottomed floor of a roughly 900-m-wide crater. The 80-m-high walls of this crater expose bedded tephra layers from phreatomagmatic eruptions. The walls of the two outer craters, which are breached to the SW, appear at the upper right.
Photo by Lee Siebert, 2002 (Smithsonian Institution).