Report on Chirpoi (Russia) — 10 September-16 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 September-16 September 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Chirpoi (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 10 September-16 September 2014. Smithsonian Institution and US Geological Survey.
46.525°N, 150.875°E; summit elev. 742 m
All times are local (unless otherwise noted)
During 1 to 16 September thermal anomalies were detected from Chirpoi in satellite images when clear conditions permitted. On 4 September SVERT increased the Aviation Color Code from Green to Yellow due to renewed activity including thermal anomalies. Gas-and-steam plumes were visible on 11 and 15-16 September.
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.