Report on Ibu (Indonesia) — January 2020
Bulletin of the Global Volcanism Network, vol. 45, no. 1 (January 2020)
Managing Editor: Edward Venzke.
Research and preparation by Paul Berger.
Ibu (Indonesia) Frequent ash plumes and small lava flows in the crater through December 2019
Please cite this report as:
Global Volcanism Program, 2020. Report on Ibu (Indonesia) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 45:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN202001-268030
Ibu
Indonesia
1.488°N, 127.63°E; summit elev. 1325 m
All times are local (unless otherwise noted)
Heightened continuing activity at Ibu since March 2018 has been dominated by frequent ash explosions with weak ash plumes, and numerous thermal anomalies reflecting one or more weak lava flows (BGVN 43:05, 43:12, and 44:07). This report summarizes activity through December 2019, and is based on data from the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC), and various satellites.
Typical ash plumes during the reporting period of July-December 2019 rose 800 m above the crater, with the highest reported to 1.4 km in early October (table 5). They were usually noted a few times each month. According to MAGMA Indonesia, explosive activity caused the Aviation Color Code to be raised to ORANGE (second highest of four) on 14, 22, and 31 August, 4 and 30 September, and 15 and 20 October.
Table 5. Ash plumes and other volcanic activity reported at Ibu during December 2018-December 2019. Plume heights are reported above the crater rim. Data courtesy of PVMBG and Darwin VAAC.
| Date | Time | Ash Plume Height | Plume Drift | Remarks |
| 11 Dec 2018 | -- | 500 m | -- | Weather clouds prevented views in satellite data. |
| 12 Jan 2019 | 1712 | 800 m | S | -- |
| 13 Jan 2019 | 0801 | 800 m | S | -- |
| 05-12 Feb 2019 | -- | 200-800 m | E, S, W | Weather conditions occasionally prevented observations. |
| 25-26 Feb 2019 | -- | 1.1-1.7 km | NE, ENE | Thermal anomaly. |
| 28 Feb 2019 | -- | 800 m | N | -- |
| 18 Mar 2019 | -- | 1.1 km | E | Plume drifted about 17 km NE. |
| 23 Mar 2019 | -- | 1.1 km | E | -- |
| 28 Mar 2019 | -- | 800 m | SE | -- |
| 10 Apr 2019 | -- | 800 m | N | -- |
| 15-16 Apr 2019 | -- | 1.1 km | N, NE | -- |
| 18 Apr 2019 | -- | 800 m | E | -- |
| 07 May 2019 | -- | 1.1 km | ESE | -- |
| 08 May 2019 | -- | 1.1 km | ESE | -- |
| 09 May 2019 | 1821 | 600 m | S | Seismicity characterized by explosions, tremor, and rock avalanches. |
| 10 May 2019 | -- | 500 m | ESE | -- |
| 14 May 2019 | 1846 | 800 m | N | -- |
| 14-16, 18-19 May 2019 | -- | 0.8-1.7 km | NW, N, ENE | -- |
| 23-24 May 2019 | -- | 1.1-1.4 km | SE | -- |
| 31 May 2019 | -- | 800 m | W | -- |
| 02 Jun 2019 | -- | 1.7 km | W | -- |
| 21 Jun 2019 | -- | 500 m | N, NE | -- |
| 24-25 Jun 2019 | -- | 0.2-1.1 km | SE, ESE | -- |
| 06 Jul 2019 | -- | 800 m | N | Intermittent thermal anomaly. |
| 15 Jul 2019 | -- | 800 m | NE | -- |
| 07-12 Aug 2019 | -- | 200-800 m | -- | Plumes were white-to-gray. |
| 14 Aug 2019 | 1107 | 800 m | N | Seismicity characterized by explosions and rock avalanches. |
| 22 Aug 2019 | 0704 | 800 m | W | Seismicity characterized by explosions and rock avalanches. |
| 31 Aug 2019 | 1847 | 800 m | N | Seismicity characterized by explosions and rock avalanches. |
| 04 Sep 2019 | 0936 | 300 m | S | -- |
| 28 Sep 2019 | -- | 500-800 m | WNW | -- |
| 30 Sep 2019 | 1806 | 800 m | N | -- |
| 06-07 Oct 2019 | -- | 0.8-1.4 km | S, N | -- |
| 15 Oct 2019 | 0707 | 400 m | S | -- |
| 20 Oct 2019 | 0829 | 400 m | W | -- |
| 01-05 Nov 2019 | -- | 200-800 m | E, N | Plumes were white-and-gray. |
| 20-21, 23-25 Nov 2019 | -- | 500-800 m | Multiple | Thermal anomaly on 21 Nov. |
| 03 Dec 2019 | -- | 800 m | NE | Thermal anomaly. |
| 26 Dec 2019 | -- | 800 m | S | Discrete ash puffs in satellite imagery. |
Thermal anomalies were sometimes noted by PVMBG, and were also frequently obvious in infrared satellite imagery suggesting lava flows and multiple active vents, as seen on 22 November 2019 (figure 19). Thermal anomalies using MODIS satellite instruments processed by the MODVOLC algorithm were recorded 2-4 days every month from July to December 2019. In contrast, the MIROVA (Middle InfraRed Observation of Volcanic Activity) system detected numerous hotspots on most days (figure 20).
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Figure 19. Example of thermal activity in the Ibu crater on 22 November 2019, along with a plume drifting SE. One or more vents in the crater are producing small lava flows, an observation common throughout the reporting period. Sentinel-2 false color (urban) images (bands 12, 11, 4), courtesy of Sentinel Hub Playground. |
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Figure 20. Thermal anomalies recorded at Ibu by the MIROVA system using MODIS infrared satellite data for the year 2019. Courtesy of MIROVA. |
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.
Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); MAGMA Indonesia, Kementerian Energi dan Sumber Daya Mineral (URL: https://magma.vsi.esdm.go.id/); Badan Nasional Penanggulangan Bencana (BNPB), National Disaster Management Agency, Graha BNPB - Jl. Scout Kav.38, East Jakarta 13120, Indonesia (URL: http://www.bnpb.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).
