Visual observations and seismicity indicated that viscous lava extrusion was probably continuing at a low level in January. Emissions from the summit consisted of moderate to strong white and occasionally brown vapours [and ash]. Weak glow from the summit was often visible at night.

Geological Summary. Bagana volcano, in a remote portion of central Bougainville Island, is frequently active. This massive symmetrical cone was largely constructed by an accumulation of viscous andesitic lava flows. The entire edifice could have been constructed in about 300 years at its present rate of lava production. Eruptive activity is characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although occasional explosive activity produces pyroclastic flows. Lava flows with tongue-shaped lobes up to 50 m thick and prominent levees descend the flanks on all sides.

Information Contacts: B. Talai and P. Lowenstein, RVO.