Tiatia

(also Chacha), an active volcano in the northeastern part of Kunashir Island (Kuril Islands, USSR). The volcano rises to a height of 1,819 m. It is distinguished by its classical shape, which is that of a “volcano within a volcano”—also called the Somma-Vesuvius formation. The evenly truncated cone of the somma, which is 1,485 m high, has a diameter of 15 to 18 km at the base, while the maximum diameter across the ring crest is 2.4 km. The central cone at the summit rises to a height of 337 m above the floor of the caldera.

Tiatia erupted in 1812 and 1973. The volcano is composed of basalt and andesite. Growing along the foothills are coniferous and broad-leaved forests with bamboo groves, while the higher slopes have thickets of Erman’s birch and dwarf stone pine.