CVGHM reported incandescence at Dukono's summit during 31 March-24 April. On 25 April, incandescent material was ejected 25 m above the summit. During 30 April-2 May seismicty increased. On 25 May, an ash plume rose to an altitude of 1.4-2.1 km (4,600-6,900 ft) a.s.l. and was accompanied by thunderous and booming sounds. On 29 May, an ash plume rose to an altitude of 2.3 km (7,500 ft) a.s.l. and again was accompanied by thunderous and booming sounds. The Alert Level was raised to 3 (on a scale of 1-4). Residents and visitors were not permitted within 3 km of the summit.

Geological Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, have occurred since 1933. During a major eruption in 1550 CE, a lava flow filled in the strait between Halmahera and the N-flank Gunung Mamuya cone. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.

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