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. 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.

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.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Badan Nacional Penanggulangan Bencana (BNPB), KompasTV