Report on Ibu (Indonesia) — 18 November-24 November 2020
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 18 November-24 November 2020
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2020. Report on Ibu (Indonesia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 18 November-24 November 2020. Smithsonian Institution and US Geological Survey.
1.488°N, 127.63°E; summit elev. 1325 m
All times are local (unless otherwise noted)
PVMBG and the Darwin VAAC reported that on 19 and 22 November ash plumes from Ibu were identified in satellite images rising to 2.1 km (7,000 ft) a.s.l. and drifting SW and W. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.
Geological Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions.