Report on Alaid (Russia) — 30 March-5 April 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 30 March-5 April 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Alaid (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 30 March-5 April 2016. Smithsonian Institution and US Geological Survey.
50.861°N, 155.565°E; summit elev. 2285 m
All times are local (unless otherwise noted)
KVERT reported that moderate activity at Alaid continued during 25 March-1 April. Satellite images showed an intense daily thermal anomaly over the volcano. A gas-and-steam plume continaing minor amounts of ash drifted about 60 km S and SW during 26 and 30-31 March. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Geologic Background. The highest and northernmost volcano of the Kuril Islands, 2285-m-high Alaid is a symmetrical stratovolcano when viewed from the north, but has a 1.5-km-wide summit crater that is breached widely to the south. Alaid is the northernmost of a chain of volcanoes constructed west of the main Kuril archipelago. Numerous pyroclastic cones dot the lower flanks of this basaltic to basaltic-andesite volcano, 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 in the Kuril Islands during historical time.