Based on observations conducted at the Karangetang Volcano Observation Post in the village of Salili, PVMBG reported that during 1 February-[15 March] the lava dome was incandescent at night. Variable amounts of white and blue emissions rose as high as 150 m above Main Crater. Seismicity was dominated by shallow volcanic earthquakes; volcanic and multi-phase earthquakes declined though signals indicated that lava-dome growth continued. Thermal anomalies had not been detected in satellite images since 8 March. The Alert Level was lowered to 2 (on a scale of 1-4); visitors and residents were warned not to approach Karangetang within a 1.5-km radius.

Geological Summary. 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. 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 (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.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)