Although there was no eruptive activity reported at Gamalama, in a 5 February press release the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) noted that the number of daily deep volcanic earthquakes had increased. A total of 36 deep volcanic earthquakes were recorded during 29 January-4 February, with the highest daily number (10) recorded on 1 February. The number of deep volcanic earthquakes generally averages 1-2 events per day. Other seismic signals were recorded during that period including three tornillo earthquakes and three earthquakes likely indicating emissions. Dense white plumes rose 200-100 m above the summit, remaining at typical levels. The Alert Level remained at 2 (on a scale of 1-4); visitors and residents were warned not to approach the crater within a 1.5-km radius.

Geological Summary. Gamalama is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera, and is one of Indonesia's most active volcanoes. The island was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the extensive documentation of activity. Three cones, progressively younger to the north, form the summit. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano; the S-flank Ngade maar formed after about 14,500–13,000 cal. BP (Faral et al., 2022). Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63.

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