Report on Alaid (Russia) — 17 October-23 October 2012
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 17 October-23 October 2012
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2012. Report on Alaid (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 17 October-23 October 2012. Smithsonian Institution and US Geological Survey.
50.861°N, 155.565°E; summit elev. 2285 m
All times are local (unless otherwise noted)
According to KVERT, observers on Paramushir Island (SE) reported weak gas-and-steam activity from Alaid during 11 and 16-17 October. A thermal anomaly on the volcano was detected in satellite imagery during 12 and 14-17 October. Cloud cover prevented observations during 19-22 October. Observers on Shumshu Island (50 km E) reported that an ash plume rose 700 m above the crater on 23 October and a thermal anomaly was detected in satellite imagery. The Aviation Color Code remained at Yellow.
Geological Summary. The highest and northernmost volcano of the Kuril Islands, Alaid is a symmetrical stratovolcano when viewed from the north, but has a 1.5-km-wide summit crater that is breached open to the south. This basaltic to basaltic-andesite volcano is the northernmost of a chain constructed west of the main Kuril archipelago. Numerous pyroclastic cones are present the lower flanks, particularly on the NW and SE sides, including an offshore cone formed during the 1933-34 eruption. Strong explosive eruptions have occurred from the summit crater beginning in the 18th century. Reports of eruptions in 1770, 1789, 1821, 1829, 1843, 1848, and 1858 were considered incorrect by Gorshkov (1970). Explosive eruptions in 1790 and 1981 were among the largest reported in the Kuril Islands.