Trezubets

(Jigoku), an active volcano on Urup Island in the Kuril Islands. The truncated central cone, which is up to 997 m high, is crowned with lava pinnacles as the result of an eruption of the summit of an extrusive dome. The volcano is composed of andesites; in the south a fragment of a somma in the form of a crescent-shaped ridge up to 1,220 m high has remained intact. The volcano was active in 1894 and 1924. There are active fumaroles and hot springs. The slopes are covered with alder groves, dwarf stone pine, and thickets of Kuril bamboo.