Report on Gorely (Russia) — 26 October-1 November 2011
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 26 October-1 November 2011
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2011. Report on Gorely (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 26 October-1 November 2011. Smithsonian Institution and US Geological Survey.
52.5549°N, 158.0358°E; summit elev. 1799 m
All times are local (unless otherwise noted)
KVERT reported that during 21-28 November seismic activity from Gorely was at moderate levels and volcanic tremor was detected. Satellite imagery showed a weak thermal anomaly over the volcano during 21-25 November. The Aviation Color Code level remained at Yellow.
Geological Summary. Gorely volcano consists of five small overlapping stratovolcanoes constructed along a WNW-ESE line within a large 9 x 13 km caldera. The caldera formed about 38,000-40,000 years ago accompanied by the eruption of about 100 km3 of tephra. The massive complex includes about 40 cinder cones, some of which contain acid or freshwater crater lakes; three major rift zones cut the complex. Another Holocene stratovolcano is located on the SW flank. Activity during the Holocene was characterized by frequent mild-to-moderate explosive eruptions along with a half dozen episodes of major lava extrusion. Early Holocene explosive activity, along with lava flows filled in much of the caldera. Quiescent periods became longer between 6,000 and 2,000 years ago, after which the activity was mainly explosive. About 600-650 years ago intermittent strong explosions and lava flow effusion accompanied frequent eruptions. Historical eruptions have consisted of moderate Vulcanian and phreatic explosions.