This paper contains a first brief description for two lava flows from the 12-15 June, 2009 catastrophic eruption produced by Sarychev Peak, Matua Island, the Central Kuriles. Previously this eruption was considered to be explosive. The flows from the eruption are about 2.4 and 2.7 km long and 100 to 150 m wide, in some places they are as wide as 350 m. The flows occupy the territory of 0.8 km2 with lava volume of 10 million km3. They travelled along sector grabens simultaneously with pyroclastic flows burning elder woods and mountain meadows and were partially overlapped by pyroclastics.

The article provides information about nival-volcanogenic, possibly glacial-volcanogenic, mudflows (lahars) on three streams on the south side of Atlasov Island (Kuril Islands, Russia). The island is an active stratovolcano Alaid, 2339 m asl high. The effusive-explosive eruption of the Alaid volcano began on September 10, 2022 and continues to the present day. Strombolian activity of the apical cone and lava outflow is observed. Lava filled the summit caldera by September 27. The lava flow then crossed the southern part of the caldera crest and began to descend down the erosional depression at the tops of the catchments of three unnamed streams. Photography and satellite images showed the presence of mudflow transformation of stream beds and slopes, and mudflows fan at the mouths of the streams. Analysis of meteorological and volcanological data showed that the formation of lahars was caused by rapid melting of snow/ice under the influence of lava flow and it occurred between September 29 and October 2.