Report on Chikurachki (Russia) — 16 April-22 April 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 16 April-22 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, 16 April-22 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 stratovolcano, located on Paramushir Island in the Northern Kuriles, began erupting on 18 April 2003. During the next few days observers described the ash falls and substantial plumes with estimated heights up to ~10 km altitude. Observers on Paramushir island saw ash explosions on 18 April; ash fell in Podgorny town and Cape Vasiliev. Satellite data for 18 April revealed that ash plumes moved towards the SSE and traveled a distance of more than 50 km. The Aviation Meteorological Center at Yelizovo airport reported that on 19 April ash plumes rose 2,000 m. Three distinct eruptive events were detected in satellite data on 19 April, in one case ash plumes extended over 50 km SE.
The longest reported plume of the week occurred on 20 April; it reached over 250 km from the volcano towards the SE, later blowing E. Satellite analysts described a variety of plumes on 21 April: a narrow ash plume (visible ~130 km in length and trending SE), a comparatively wide ash plume (~ 25 km wide at a distance of ~50 km from the volcano), and some other ash plumes (over 50-70 km in length moving to the S). One reason why this eruption and its plumes are important is because they lie along a frequently traveled aviation route.
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.