Report on Chikurachki (Russia) — 23 April-29 April 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 April-29 April 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Chikurachki (Russia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 23 April-29 April 2003. Smithsonian Institution and US Geological Survey.
50.324°N, 155.461°E; summit elev. 1781 m
All times are local (unless otherwise noted)
Chikurachki, a volcano located on Paramushir Island in the North Kuriles, began erupting on 18 April 2003. A KVERT update for 25 April stated that the eruption continued and satellite data confirmed that ash plumes had moved SE and occasionally E during 22-25 April. The plumes attained lengths over 100 km. On 22 April observers at Vasiliev Cape on Paramushir Island saw a white gas-steam plume rise 500 m above the volcano's crater.
Geologic Background. Chikurachki, the highest volcano on Paramushir Island in the northern Kuriles, is actually a relatively small cone constructed on a high Pleistocene volcanic edifice. Oxidized basaltic-to-andesitic scoria deposits covering the upper part of the young cone give it a distinctive red color. Frequent basaltic plinian eruptions have occurred during the Holocene. Lava flows from 1781-m-high Chikurachki reached the sea and form capes on the NW coast; several young lava flows also emerge from beneath the scoria blanket on the eastern flank. The Tatarinov group of six volcanic centers is located immediately to the south of Chikurachki, and the Lomonosov cinder cone group, the source of an early Holocene lava flow that reached the saddle between it and Fuss Peak to the west, lies at the southern end of the N-S-trending Chikurachki-Tatarinov complex. In contrast to the frequently active Chikurachki, the Tatarinov volcanoes are extensively modified by erosion and have a more complex structure. Tephrochronology gives evidence of only one eruption in historical time from Tatarinov, although its southern cone contains a sulfur-encrusted crater with fumaroles that were active along the margin of a crater lake until 1959.