The edifice of Chirinkotan volcano at sea level has a diameter of 2.5-3 km and an area of 6 square kilometers. Although the top of the volcano rises to 724 m, the actual height of the cone from the bottom of the sea is about 3000 m. On the top of the cone, on the western side, traces of a large explosive crater with a diameter of about 1 km are visible. In this crater, the remains of the inner dome rise, which at one time completely or almost entirely filled the crater. Later, a large part of the inner cone was blown up, and at present there is a large amphitheater at the top of an open south crater with a diameter of about 0.8 km. The bottom of this crater is more or less flat, cut by valleys of hot streams, in places there are small mineralized lakes. At the edges of the crater - near the walls of the amphitheater, outcrops of powerful fumaroles are marked.
At the northern foot of the inner cone, approximately on the crest of the old crater, there is a side cone, which gave lava flows that descended to the northern coast of the island. Fresh lava flows also descend along the southeastern slope of the volcano. These streams poured out of the inner cone; now their origins are cut off by the crest of a new explosive crater. In all likelihood, the outpouring of precisely these flows was observed in the 80s of the XIX century by Captain Snow. At that time, the inner cone was still intact. According to the description of Snow (1902), “it is a double volcanic cone, of which the outer one collapsed from the southeast side. Smoke comes from the crater, and sometimes lava breaks out through the gap in the crater and flows along the sides of the mountain into the sea. ” Snow sailed on the Kuril Islands between 1878 and 1889. Unfortunately, he does not give exact dates of eruptions.
At the bottom of the modern crater in 1961, G.E. Bogoyavlenskaya discovered a small fresh slag cone with a lava flow. This cone was formed, possibly in 1955, since in 1954 we did not see it. Lava flow is composed of piroxen-hornblende andesite.
References
Горшков Г.С. Вулканизм Курильской островной дуги / Отв. ред. Рудич К.Н. М.: Наука. 1967. 288 с.  |
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| Ash clouds, ash falls, pyroclastic flows, hot avalanches and lahars are a potential hazard associated with explosive eruptions of this volcano. The volcano poses a potential hazard to international and local airlines passing in the Kuriles region, since the height of its ash emissions can reach 10-15 km above sea level, ash plumes and clouds can drift hundreds of kilometers from the volcano in different directions. In addition, the outflow of lava flows onto the slopes of the volcano and the surrounding area is possibly. |
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