Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 18-23 July ash plumes from Dukono rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted NW, N, NE, and E.

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)