Report on Ibu (Indonesia) — 13 May-19 May 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
13 May-19 May 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Ibu (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 13 May-19 May 2020. Smithsonian Institution and US Geological Survey.
1.488°N, 127.63°E; summit elev. 1325 m
All times are local (unless otherwise noted)
The Darwin VAAC reported that on 16 May an ash plume from Ibu rose to 1.8 km (6,000 ft) a.s.l. and drifted NW based on satellite images and weather models. Later that day an ash plume rose to 13.7 km (45,000 ft) a.s.l., detached from the volcano and drifted S, and quickly dissipated. Ash plumes rose to 4.3 (14,000 ft) a.s.l. and drifted W during 17-18 May. 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.