Report on Chirpoi (Russia) — 5 December-11 December 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 December-11 December 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Chirpoi (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 December-11 December 2012. Smithsonian Institution and US Geological Survey.
46.525°N, 150.875°E; summit elev. 742 m
All times are local (unless otherwise noted)
SVERT reported that a thermal anomaly was detected over Snow, a volcano of Chirpoi, during 3-4, 6, and 8 December; cloud cover prevented observations of the volcano on other days during 2-10 December.
Geologic Background. Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. The symmetrical Cherny volcano, which forms the 691 m high point of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No historical eruptions are known from 742-m-high Brat Chirpoev, but its youthful morphology suggests recent strombolian activity.