Bagana

Researchers estimate that Bagana's entire 1,855-meter edifice could have been constructed in approximately 300 years at its present rate of lava production, making it one of the youngest major volcanic structures on Earth.

Bagana has been in near-continuous eruption since February 2000 — a sustained eruptive episode spanning over 25 years as of 2025.

The volcano's lava flows are exceptionally thick, forming tongue-shaped lobes up to 50 m (160 ft) with prominent levees, reflecting the high viscosity of its andesitic magma.

Bagana is classified as a lava cone rather than a stratovolcano because its edifice is built almost entirely from accumulated lava flows rather than alternating lava and pyroclastic layers.

The 1952 eruption, rated VEI 4, was Bagana's most powerful recorded explosive event and a rare departure from its typically effusive eruption style.

Bougainville Island receives over 3,000 mm of rainfall annually, creating persistent lahar hazards as water interacts with fresh volcanic deposits on Bagana's flanks.

Bagana is one of the least accessible major active volcanoes in the world — there are no roads to the volcano, and it is surrounded by dense tropical rainforest.

The Autonomous Region of Bougainville voted overwhelmingly for independence from Papua New Guinea in a 2019 referendum; the volcano's ongoing activity adds natural hazard concerns to this political transition.

From 1972 to 1995, Bagana maintained a continuous eruption lasting 23 years before a brief pause, then resumed in 2000.

Satellite thermal monitoring is the primary method of tracking Bagana's activity, as ground-based instruments are impractical in the remote rainforest setting.