🌋VolcanoAtlas

Ulawun

The Tallest and Most Dangerous Volcano of the Bismarck Arc

Elevation

2,334 m

Last Eruption

2025

Type

Stratovolcano

Country

Papua New Guinea

Location

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Volcanic Hazards & Risk Assessment

Primary Hazards

  • Pyroclastic flows
  • Lava flows
  • Volcanic bombs and ballistics
  • Lahars and mudflows

Risk Level

Population at RiskLow
Infrastructure RiskHigh
Aviation RiskSignificant

Geological Composition & Structure

Rock Types

Primary
Unknown
Silica Content
Varied composition

Tectonic Setting

Unknown
Intraplate setting with hotspot or regional volcanic activity.

Age & Formation

Epoch
Unknown
Evidence
Unknown

Eruption Statistics & Analysis

MetricValueGlobal RankingSignificance
Total Recorded EruptionsUnknownLowModerately active volcano
Maximum VEIVEI UnknownMinorLocal impact potential
Recent Activity1 years agoVery RecentCurrently active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program
International eruption database

Current Status

Active
Recent volcanic activity detected. Continuous monitoring in place.

Authority Sources

Smithsonian GVP
Official volcano database

Related Volcanoes

All Papua New Guinea Volcanoes
Explore by country
Stratovolcano Volcanoes
By volcano type
New Britain, Bismarck Archipelago
Regional volcanoes

Other Volcanoes in Papua New Guinea

Interesting Facts

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Ulawun was designated a UN Decade Volcano in the 1990s — one of only 16 volcanoes worldwide selected for their exceptional combination of hazard and proximity to populations.

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The June 2019 VEI 4 eruption sent an ash plume to approximately 19 km (63,000 ft) altitude and forced the evacuation of approximately 11,000 people.

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Ulawun is the tallest volcano in the Bismarck volcanic arc, rising 2,334 m from near sea level to create over 2,300 m of vertical relief.

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The volcano is known locally as 'The Father,' paired with neighboring Bamus volcano (2,248 m), called 'The South Son,' in local Melanesian tradition.

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A prominent E–W escarpment on Ulawun's southern flank suggests past large-scale sector collapse — the potential recurrence of this is the volcano's most catastrophic assessed hazard.

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Before 1970, Ulawun's historical eruptions were mildly explosive (VEI 2); since then, multiple VEI 3–4 events have occurred, representing a significant escalation.

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Ulawun has produced 50 recorded eruptions since 1700, making it one of Papua New Guinea's most frequently active volcanoes.

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Papua New Guinea hosts 39 Holocene volcanoes — the seventh-highest national volcano count in the world.

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The 2000 and 2019 VEI 4 eruptions produced pyroclastic flows of basaltic composition — demonstrating that basaltic volcanoes can generate this lethal hazard.

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A catastrophic flank collapse at Ulawun could generate a tsunami in the Bismarck Sea, potentially affecting coastal communities hundreds of kilometers away.

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The upper 1,000 m of Ulawun's cone is completely unvegetated, stripped bare by frequent recent eruptions.

Frequently Asked Questions

Is Ulawun still active?
Yes, Ulawun is one of the most actively erupting volcanoes in Papua New Guinea. It produced confirmed eruptions in 2025 and has erupted frequently throughout the 2020s, including VEI 3 events in 2023. The volcano has 50 recorded eruptions since 1700 and has shown an escalation in eruption magnitude since the 1970s, including VEI 4 events in 2000 and 2019. The Rabaul Volcanological Observatory monitors the volcano continuously, and further eruptions are considered highly likely.
Why is Ulawun called a Decade Volcano?
Ulawun was designated a United Nations Decade Volcano in the 1990s as part of the International Decade for Natural Disaster Reduction. It was one of only 16 volcanoes worldwide selected for intensive study because they posed exceptional risks to nearby populations. Ulawun qualified due to its demonstrated explosive capability (VEI 4), proximity to populated coastal communities on New Britain, high eruption frequency, and the assessed risk of catastrophic flank collapse that could trigger tsunamis in the Bismarck Sea. The designation aimed to improve monitoring, hazard assessment, and emergency preparedness.
What happened in the 2019 Ulawun eruption?
On June 26, 2019, Ulawun produced a major VEI 4 eruption that sent an ash plume to approximately 19 km (63,000 ft) above sea level — well into the stratosphere. Pyroclastic flows descended the flanks, and heavy ashfall impacted communities across northern New Britain. Approximately 11,000 people were evacuated from surrounding villages to emergency shelters. The eruption destroyed gardens, contaminated water sources, and damaged buildings. Aviation warnings were issued across the southwestern Pacific, and international aid agencies assisted with the humanitarian response. It was Ulawun's largest eruption since 2000.
Could Ulawun cause a tsunami?
Yes, this is one of Ulawun's most concerning potential hazards. A prominent escarpment on the volcano's southern flank suggests past large-scale sector collapse. If a major portion of the volcanic edifice were to collapse into the Bismarck Sea, it could generate a tsunami affecting coastal communities across the region. While this scenario is low-probability in any given year, its consequences would be catastrophic. This flank-collapse risk was a key factor in Ulawun's designation as a UN Decade Volcano. More frequent hazards include pyroclastic flows, ashfall, and lava flows from the volcano's regular eruptions.
How tall is Ulawun?
Ulawun rises to 2,334 m (7,657 ft) above sea level, making it the tallest volcano in the Bismarck volcanic arc. Because the volcano rises from near sea level on the coast of New Britain, it has over 2,300 m of vertical relief — an imposing presence on the island's northern skyline. Neighboring Bamus volcano ('The South Son') is slightly shorter at 2,248 m. For comparison, Papua New Guinea's tallest volcano overall is Mount Giluwe at 4,368 m, an extinct shield volcano in the Highlands.
Where is Ulawun located?
Ulawun is located on the north coast of New Britain, the largest island in the Bismarck Archipelago of Papua New Guinea. Its coordinates are 5.05°S, 151.33°E. The nearest major town is Rabaul, approximately 130 km to the east, though smaller communities and plantations are located much closer along the coast. New Britain is situated in the southwestern Pacific, northeast of the Papua New Guinea mainland. The volcano is part of the Bismarck volcanic arc, formed by the subduction of the Solomon Sea Plate beneath the South Bismarck Plate.
What type of volcano is Ulawun?
Ulawun is a stratovolcano (composite volcano), built from alternating layers of basaltic-to-andesitic lava flows and pyroclastic deposits. It has a symmetrical conical shape with steep upper slopes stripped bare of vegetation by frequent eruptions. The summit hosts a crater that has been repeatedly modified by eruptions since 1970. Despite its basaltic composition — typically associated with gentler eruptions — Ulawun has produced explosive VEI 4 events with pyroclastic flows, demonstrating that basaltic stratovolcanoes can be highly dangerous.
How many people live near Ulawun?
Several thousand people live in coastal villages and plantation communities in the immediate vicinity of Ulawun on the north coast of New Britain. The 2019 VEI 4 eruption forced the evacuation of approximately 11,000 people, giving an indication of the population within the broader hazard zone. The nearest major town is Rabaul (~130 km east), though smaller settlements are much closer. The local economy is based on subsistence agriculture and commercial plantations (oil palm, cocoa, coconut). Papua New Guinea's limited infrastructure makes evacuation and disaster response particularly challenging.