Global Volcanism Program | Image GVP-02431
The summit of Plosky Tolbachik contains a 3-km-wide caldera whose floor is covered by the glacier in the foreground. It contains a nested inner 1.8-km-wide caldera (center) with a crater that increased substantially in size during the 1975-76 eruption. Ostry Tolbachik stratovolcano towers west of the inner caldera of Plosky Tolbachik in this 1990 view.
Photo by Dan Miller, 1990 (U.S. Geological Survey).