|Archipelago||Chornye Bratja Islands ( Kuril Islands )|
Tschirpoi ( Russian Чирпой , Japanese 知 理 保 以 島 , Chirihoi-tō ) is a 21 km² volcanic island of the Kuriles . Tschirpoi lies within the Kuril Range south of Simushir and north of Urup . Administratively, the island belongs to the Sakhalin Oblast of the Russian Federation .
Tschirpoi lies in the center of two overlapping calderas that are largely below sea level. The somewhat smaller island of Brat Tschirpojew ("brother of Tschirpoi") in the south lies on the edge of the calderas, which are 8 to 9 kilometers in diameter. The two sister islands are separated from each other by Snou Street . Both islands and other smaller islets are collectively referred to as the Tschornyje Bratja Islands (in Russian Čërnye Brat'ja - "Black Brothers").
Two volcanoes on Tschirpoi were active in historical times. The peak of the 691 meter high symmetrical volcano Cherny forms the highest point on the island. The stratovolcano had two eruptions during the 18th and 19th centuries. The youngest volcano on the island, Snow with a height of 395 meters, was formed between 1770 and 1810 on the southern slope of the Cherny. It consists almost entirely of lava flows , many of which have reached the sea on the south coast. In 1982 an eruption of the Snow was observed from a ship. According to satellite images, a lava flow may have flowed down the southeast slope of Snow in November 2012.