Global Volcanism Program | Image GVP-03290
South Inyo Crater, one of a chain of small phreatic explosion craters at the southern end of the Inyo Craters chain of lava domes and flows, is partially filled by a shallow lake. The 200-m-wide South Inyo Crater was formed when groundwater interacted with magma from a shallow dike. That interaction fed a powerful explosive eruption that concluded with the emplacement of obsidian lava domes and flows to the north of this crater.
Photo by Larry Mastin, 1992 (U.S. Geological Survey).