Report on Chikurachki (Russia) — 12 September-18 September 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 September-18 September 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Chikurachki (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 12 September-18 September 2007. Smithsonian Institution and US Geological Survey.
50.324°N, 155.461°E; summit elev. 1781 m
All times are local (unless otherwise noted)
KVERT reported that explosions from Chikurachki produced ash plumes that were visible on satellite imagery drifting SE on 7 September and ESE on 8 September. Based on visual observations, ash plumes rose to an altitude of 2.3 km (7,500 ft) a.s.l. on 8 and 11 September. Clouds obscured views during 9-10 and 12-13 September. The Level of Concern Color Code remained at Orange.
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.