Based on analyses of satellite imagery, the Darwin VAAC reported that during 23-24 and 29 June ash plumes from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 120-225 km W.

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, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the north-flank cone of Gunung Mamuya. 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: Darwin Volcanic Ash Advisory Centre (VAAC)