Volcanoes in Papua New Guinea

Papua New Guinea has 39 Holocene volcanoes catalogued by the Smithsonian Global Volcanism Program, making it the seventh most volcanically active country in the world and by far the most volcanically prolific nation in the southwestern Pacific. Despite having fewer volcanoes than countries like the [[country:united-states|United States]] (165) or [[country:japan|Japan]] (105), PNG punches far above its weight in eruption frequency: its 261 confirmed eruptions yield an average of nearly 7 eruptions per volcano — one of the highest ratios on Earth. Four PNG volcanoes are among the most active on the planet: [[volcano:ulawun|Ulawun]] (47 eruptions), [[volcano:manam|Manam]] (41 eruptions), [[volcano:langila|Langila]] (26 eruptions), and [[volcano:bagana|Bagana]] (25 eruptions).

The country’s volcanoes are distributed across several island arcs in the Bismarck Sea and Solomon Sea regions, with the island of New Britain hosting the densest concentration of active centers.

PNG’s volcanic history is punctuated by catastrophic events that rank among the largest in the Pacific during the Holocene. Eight eruptions have reached VEI 6 — a remarkably high count for a single country — including the devastating ~1660 CE Long Island eruption and the ~683 CE Rabaul caldera collapse. The 1951 eruption of [[volcano:lamington|Lamington]] killed nearly 3,000 people and was one of the deadliest volcanic disasters of the 20th century.

The 1994 [[volcano:rabaul|Rabaul]] eruption forced the evacuation of the entire city of Rabaul (population ~17,000), transforming the former provincial capital into a ghost town buried under meters of ash. Today, monitoring is conducted by the Rabaul Volcanological Observatory (RVO), which watches over this exceptionally active volcanic landscape with limited but dedicated resources. PNG’s volcanoes sit squarely within the [[special:ring-of-fire|Ring of Fire]], along one of its most complex tectonic junctions.

Papua New Guinea’s intense volcanic activity is the product of one of the most tectonically complex convergent plate boundaries on Earth. The country sits at the collision zone of multiple microplates — the Pacific, Solomon Sea, South Bismarck, and North Bismarck plates — all interacting with the Indo-Australian Plate. This complex mosaic of subduction zones, transform faults, and spreading centers generates more volcanic arcs per unit area than almost any other region on the planet.

The primary volcanic arc is the Bismarck Volcanic Arc, extending along the northern coast of New Britain and westward through the Bismarck Sea. This arc is generated by the northward subduction of the Solomon Sea Plate beneath the South Bismarck Plate. Ulawun, Rabaul, Langila, and most of New Britain’s volcanoes belong to this system.

The Bougainville Volcanic Arc runs through Bougainville Island where the Pacific Plate subducts westward. Bagana, Balbi, Billy Mitchell, and Loloru sit on this arc.

Convergence rates in the PNG region are among the highest on Earth — the Pacific Plate moves westward at approximately 10 cm per year relative to the Indo-Australian Plate. The Solomon Sea Plate subducts at 7–10 cm per year. These rapid rates drive high magma production and correspondingly frequent eruptions.

The crust beneath PNG’s arcs is predominantly oceanic to transitional (15–25 km thick), which allows basaltic to andesitic magmas to reach the surface more readily than through thick continental crust. This explains the predominantly andesitic compositions of PNG’s arc volcanoes, compared to the more evolved dacitic and rhyolitic compositions common in continental-arc countries like [[country:chile|Chile]].

**Rabaul** — [[volcano:rabaul|Rabaul]] caldera on the northeastern tip of New Britain is PNG’s most historically significant volcanic center. The 688-m-high asymmetrical shield contains a broad harbor — actually a flooded caldera — that served as the island’s largest city until 1994, when simultaneous eruptions from Vulcan and Tavurvur buried much of the town. The caldera has 19 confirmed eruptions and a VEI max of 6, including a massive caldera-forming eruption around 683 CE.

**Ulawun** — [[volcano:ulawun|Ulawun]], known locally as ‘The Father,’ is the tallest volcano in the Bismarck arc at 2,334 m (7,657 ft) and one of PNG’s most frequently active with 47 confirmed eruptions. This symmetrical [[special:types-of-volcanoes|stratovolcano]] is designated a Decade Volcano due to its explosive history and proximity to populated areas. It erupted most recently in 2025.

**Manam** — [[volcano:manam|Manam]] is a 10-km-wide volcanic island 13 km off the mainland coast and one of PNG’s most dangerous volcanoes. With 41 confirmed eruptions including three VEI 4 events (1919, 2004, 2014), Manam has repeatedly displaced its island population. The 2004 eruption forced evacuation of all ~9,000 residents, many of whom remain displaced.

**Bagana** — [[volcano:bagana|Bagana]] on Bougainville is one of the youngest and most continuously active volcanoes in PNG. This 1,855-m lava cone may have built its entire edifice in approximately 300 years through persistent andesitic lava extrusion. With 25 confirmed eruptions and ongoing 2025 activity, Bagana produces persistent lava flows, Vulcanian explosions, and pyroclastic flows.

**Lamington** — [[volcano:lamington|Lamington]]’s January 21, 1951, eruption was one of the deadliest volcanic disasters of the 20th century. The VEI 4 Plinian eruption generated pyroclastic flows that devastated 230 km², killing approximately 2,942 people. The eruption was especially lethal because Lamington was not recognized as active beforehand.

**Long Island** — This volcanic complex hosts a massive 10 × 12.5 km caldera now filled by Lake Wisdom. The ~1660 CE eruption (VEI 6) was one of the largest volcanic events in the Pacific during the last millennium. With 11 confirmed eruptions including two VEI 6 events, Long Island demonstrates PNG’s capacity for truly catastrophic events.

**Langila** — One of New Britain’s most frequently active volcanoes with 26 confirmed eruptions through 2025. Four overlapping composite cones produce persistent Strombolian to Vulcanian eruptions.

**Witori** — The Witori caldera has produced three VEI 6 eruptions in ~5,000 years (~4000 BCE, ~1370 BCE, 710 CE) — an exceptional rate of catastrophic activity. The active Pago cone within the caldera last erupted in 2012.

**Billy Mitchell** — This Bougainville caldera produced a VEI 6 eruption around 1580 CE. Quiet since then, it represents a potentially dangerous ‘sleeping giant.’

**Kadovar** — This small volcanic island erupted dramatically in 2018 after centuries of dormancy, forcing evacuation of its ~600 residents. Activity continued through 2023.

Papua New Guinea’s volcanic eruption history is one of the most violent in the Pacific, with 261 confirmed eruptions across 39 volcanoes. The country has produced 8 VEI 6 eruptions during the Holocene — rivaling [[country:indonesia|Indonesia]] — alongside 4 VEI 5, 19 VEI 4, and 36 VEI 3 events. The VEI distribution is dominated by moderate explosive eruptions (127 events at VEI 2, 49% of eruptions with assigned VEI).

The largest Holocene eruptions include Witori’s three VEI 6 events (~4000 BCE, ~1370 BCE, 710 CE), Dakataua (~653 CE, VEI 6), Rabaul (~683 CE, VEI 6), Long Island (~2040 BCE and ~1660 CE, both VEI 6), and Billy Mitchell (~1580 CE, VEI 6). These collectively demonstrate that PNG’s arcs produce Krakatoa-scale explosions with alarming regularity.

The historical period saw devastating activity: the 1937 Rabaul eruption killed 507 people; the 1951 Lamington disaster killed 2,942; the 1994 Rabaul eruption buried the city. The 21st century has maintained PNG’s high eruption tempo: Manam’s 2004 VEI 4 eruption displaced the entire island population; Ulawun erupted explosively in 2019 with a 19-km column; Kadovar’s unexpected 2018 eruption evacuated its island. As of 2025, four PNG volcanoes are simultaneously active: Ulawun, Bagana, Manam, and Langila.

Papua New Guinea faces a comprehensive spectrum of volcanic hazards compounded by challenging island geography, limited infrastructure, and isolated communities. Pyroclastic flows represent the greatest lethal threat, as demonstrated by the 1951 Lamington disaster (2,942 deaths). The steep-sided andesitic stratovolcanoes of the Bismarck arc are all capable of generating devastating pyroclastic flows.

Tephra fall persistently affects agriculture and infrastructure. The 1994 Rabaul eruption deposited meters of wet ash that collapsed buildings. Volcanic tsunamis pose particular danger in PNG’s island setting — the ~1660 CE Long Island eruption generated a tsunami, and the 1888 Ritter Island collapse produced a massive debris avalanche and tsunami.

Volcanic gas emissions affect communities downwind of persistently degassing volcanoes.

The Rabaul Volcanological Observatory (RVO) monitors PNG’s volcanoes using seismometers, tiltmeters, and visual observations, supplemented by satellite monitoring from international partners including the Australian Bureau of Meteorology, [[ext:https://www.usgs.gov/programs/volcano-hazards|USGS]], and Japan Meteorological Agency. PNG’s total population at volcanic risk is estimated at several hundred thousand.

PNG’s volcanoes span four provinces. The Bismarck Volcanic Arc along New Britain’s north coast is the most active zone, hosting Ulawun, Rabaul, Langila, Witori, Bamus, Karkar, and Dakataua. The Bougainville Volcanic Arc hosts Bagana, Balbi (PNG’s tallest at 2,715 m), Billy Mitchell, and Loloru.

The Trobriand Volcanic Province on the Papuan mainland includes Lamington, Victory, and Dawson Strait Group. The Bismarck Sea Volcanic Province includes submarine and near-sea-level features. Manam, Karkar, Long Island, Bam, and Kadovar form a chain extending north from the mainland into the Bismarck Sea.

Volcanoes have profoundly shaped Papua New Guinea’s diverse indigenous communities. The Tolai people of Rabaul have coexisted with the caldera for millennia, and their oral traditions include eruption accounts. The 1994 eruption displaced the entire community and shifted the provincial capital to Kokopo.

On Manam Island, ~9,000 residents evacuated in 2004 remain largely displaced — one of the Pacific’s longest-running volcanic displacement crises. Volcanic soils support productive agriculture, particularly cocoa and copra in the Gazelle Peninsula. PNG’s volcanic landscapes are increasingly recognized for tourism potential, though infrastructure remains limited.

Volcanic tourism in Papua New Guinea requires adventurous preparation and tolerance for basic infrastructure. Rabaul on New Britain, accessible by air from Port Moresby, offers the most developed experiences: the buried old town, Tavurvur cone viewpoints, the volcanological observatory, and hot springs. The Rabaul area includes World War II sites from the Japanese occupation.

More remote volcanoes require charter flights or boats. Visitors should check alert levels with the Rabaul Volcanological Observatory, travel with local guides, and prepare for unpredictable logistics. The dry season (May–October) offers the best conditions.