Report on Chikurachki (Russia) — 17 August-23 August 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 August-23 August 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Chikurachki (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 17 August-23 August 2016. 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 strong gas-and-steam emissions from Chikurachki were visible during 1132-1700 on 18 August. Ash was visible in the plume beginning at 1720, prompting KVERT to raise the Aviation Color Code to Orange (the second highest level on a four-color scale). The ash plume rose over 2.7 km above the crater and drifted 280 km NE. Ashfall was reported in Severo-Kurilsk (Paramushir Island). Ash was no longer detected in the plume starting at 2330 on 19 August; the Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale), and then to Green on 21 August.
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.