Thermal anomalies at Dukono were reported on nine days between 10 August and 27 October 2007 and an ash plume occurred in June 2007 (BGVN 32:10). This report discusses activity from late November 2007 through early October 2008.

MODIS-MODVOLC thermal alerts were recorded on 12 December 2007 and 31 January 2008. Between 31 March and 24 April 2008 the Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported incandescence at the summit. On 25 April, incandescent material was ejected 25 m above the summit. Seismicity increased during 30 April-2 May.

On 25 May, an ash plume rose to an altitude of 1.4-2.1 km and was accompanied by thunderous and booming sounds. An ash plume on 29 May rose to an altitude of 2.3 km 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. Satellite imagery detected hotspots through 26 May 2008 (table 7).

Table 7. Thermal anomalies at Dukono based on MODIS-MODVOLC imaging between 27 November and 6 October 2008 (continued from the lists in BGVN 32:03 and 32:10). Courtesy of Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System.

According to the CVGHM, during 30 May-12 June, seismicity decreased and white plumes were observed at altitudes of 1.4-1.8 km when clouds did not inhibit observations. Because of decreased seismic activity, on 13 June the Alert Level was decreased to 2. Residents and visitors were not permitted within 2 km of the summit.

No further reports were issued by CVGHM through 6 October 2008. However, the Darwin Volcanic Ash Advisory Centre reported that satellite imagery had detected ash plumes during 25 July-6 October (table 8).

Table 8. Ash plumes reported from Dukono during 25 July-6 October 2008 (UTC). Data from the Darwin Volcanic Ash Advisory Centre.

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.

Information Contacts: Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://vsi.esdm.go.id/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), University of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).