|The volcano has a structure of the Somme-Vesuvius type. A somma with a diameter of 2 km was preserved only on the southeast side, its eastern and western parts are hidden under the deposits of the young cone. The central cone rises to 1205 m above sea level, or about 300 m above the crest of the caldera. In the southeast, between the crest of the somma and the slope of the central cone, there is a small flat atrio, and in the northwest the slopes of the cone descend to the seashore and then, without interruption and without underwater terraces, go to a depth of more than 1000 m. Crater of the central cone elongated from southwest to northeast and has the shape of an oval funnel 400 X 500 m in size with a depth of more than 100 m. In the northeast and southwest, the crater ridge has noticeable depressions; a large pothole stretches along the slope to the northwest of the crater; similar potholes are also found in the northwest of the cone. The slopes are covered mainly with slag and slag bombs. In the cliffs of the crater walls and the sources of the potholes, layers of lava flows are exposed. The ends of the flows, sometimes with a wavy surface, emerge on the seashore.
Горшков Г.С. Вулканизм Курильской островной дуги / Отв. ред. Рудич К.Н. 1967. 288 с.
Горшков Г.С. Каталог действующих вулканов Курильских островов // Бюллетень вулканологических станций. 1957. № 25. С. 96-178.