According to KVERT, observers on Paramushir Island reported that on 5 October a large gas-and-steam plume from Alaid rose 200 m above the crater. A thermal anomaly on the volcano was detected in satellite imagery for 7.5 hours the next day. The increased activity prompted KVERT to raise the Aviation Color Code to Yellow on 7 October. Satellite imagery detected a thermal anomaly on 15 October.

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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)