4. Tolbachik complex volcano.The
Tolbachik massif is composed of two overlapping, but morphologically
dissimilar volcanoes. The flat-topped Plosky Tolbachik shield volcano with
its nested Hawaiian-type calderas up to 3 km in diameter is located east
(right) of the older and higher sharp-topped Ostry Tolbachik stratovolcano.
The 1975-76 eruption from the summit and
SSW-flank fissures was the largest historical basaltic eruption in Kamchatka.
Photo by Oleg Volynets, Institute of Volcanology, Petropavlovsk; data from
Smithsonian Global Volcanism Program.