Report on Karangetang (Indonesia) — 6 February-12 February 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 February-12 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, 6 February-12 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)
On 8 February PVMBG reported that lava from Karangetang’s Kawah Dua (North Crater) continued to advance over 3.5 km down the Malebuhe River drainage on the NW flank into the ocean. Levees had formed at the margins channeling the lava down the middle of the flow. Avalanches from the edges of the flow generated brown and gray plumes. A lava delta was building out into the ocean and generating a dense steam plume. Drone footage acquired on 9 February showed that the flow was about 160 m wide where it crossed a road (about 210 m from the coast) and about 140 m wide at the coast. Seismicity remained high. The Alert Level remained at 3 (on a scale of 1-4), and residents were warned to remain outside of the 2.5-km exclusion zone around the N and S craters, and not enter within 3 km WNW and 4 km NW.
Geologic Background. Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, about 125 km NNE of the NE-most point of Sulawesi island. 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 have produced pyroclastic flows.