The first recorded eruption of Ulawun was by Dampier in 1700. The next record was 178 years later. A large eruption in 1915 deposited 10 cm of ash at Toriu, 50 km northeast of the volcano. In 1970 a large eruption produced nuees ardentes and lava flows. The eruption devastated the NW flank of Ulawun and modified the summit crater.
An eruption in 1980 ejected ash to 60,000 ft and produced pyroclastic flows which swept all flanks of the volcano and devastated an area of 20 sq km. The most serious volcanic hazard at Ulawun volcano is catastrophic structural collapse, producing an eruption which could devastate hundreds of sq km in area.
Ulawun volcano is 400 m higher than most of the volcanoes in the Bismarck which indicates it may be at the limit of structural stability.
2010 Activity
On 14-15 February 2010 ash emissions from Ulawun volcano reached a height of 3.7 km and drifted 95 km.
2009 Earthquake
A magnitude 5.1 earthquake hit 10 km west of Ulawun volcano on 28th May 2009.
2008 Activity
Seismic activity remained high at Ulawun Volcano in July 2008.