Report on Karangetang (Indonesia) — 30 January-5 February 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 30 January-5 February 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Karangetang (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 30 January-5 February 2019. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
PVMBG reported that the current eruption at Karangetang began with increased seismicity and thermal anomalies in November 2018. Since then activity was dominated by lava-dome growth, avalanches, and pyroclastic flows. A gray ash plume rose above the summit craters on 30 January. By 2 February ’a’a lava from Kawah Dua (North Crater) had traveled 2.5 km NNW down the Melebuhe River drainage, prompting the evacuation of eight families (about 21 people). A section of the local road was closed, from W of the Batuare River to Kali Melebuhe. According to a news article the flow was 50 m thick in some areas. Seismic signals indicating avalanches sharply increased on 3 February. Lava and pyroclastic flows originated from the Kawah Dua crater, traveling as far as 1 km W down the Sumpihi River drainage, 2 km NW down the Batuare River, and 2.9 km NW down the Malebuhe drainage. BNPB reported that 112 residents (from Niambangeng, Kampung Beba, and Batubulan villages) had evacuated by 1730 on 4 February, and according to a news article the lava crossed the highway at 1800. The lava flow continued to progress and reached the ocean during 5-6 February.
Geologic Background. Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, north of Sulawesi. The stratovolcano contains five summit craters along a N-S line. It is one of Indonesia's most active volcanoes, with more than 40 eruptions recorded since 1675 and many additional small eruptions that were not documented in the historical record (Catalog of Active Volcanoes of the World: Neumann van Padang, 1951). Twentieth-century eruptions have included frequent explosive activity sometimes accompanied by pyroclastic flows and lahars. Lava dome growth has occurred in the summit craters; collapse of lava flow fronts has also produced pyroclastic flows.