🌋VolcanoAtlas

Rabaul

The Caldera That Destroyed a City

Elevation

688 m

Last Eruption

2014

Type

Caldera

Country

Papua New Guinea

Location

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Volcanic Hazards & Risk Assessment

Primary Hazards

  • Pyroclastic flows and surges
  • Large explosive eruptions (VEI 4+)
  • Ash fall and tephra deposits
  • Lahars and debris flows

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 Activity12 years agoRecentRecently active

Monitoring & Alert Status

Monitoring Networks

Global Volcanism Program
International eruption database

Current Status

Watch
Dormant but monitored. Capable of renewed activity.

Authority Sources

Smithsonian GVP
Official volcano database

Related Volcanoes

All Papua New Guinea Volcanoes
Explore by country
Caldera Volcanoes
By volcano type
Bismarck Volcanic Arc
Regional volcanoes

Other Volcanoes in Papua New Guinea

Interesting Facts

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The 1994 eruption of Rabaul was one of volcanology’s great success stories — decades of monitoring meant only 5 people died in an eruption that destroyed an entire city of 30,000.

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Both the 1937 and 1994 eruptions featured simultaneous eruptions from Vulcan and Tavurvur cones on opposite sides of the caldera, suggesting a connected magma system.

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The caldera-forming eruption of ~683 CE reached VEI 6, comparable in magnitude to the 1991 eruption of Mount Pinatubo.

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Rabaul’s Blanche Bay is actually a flooded caldera floor, created when it collapsed below sea level during the 683 CE eruption.

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During World War II, Rabaul served as a major Japanese military base with extensive tunnel networks still visible today.

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The Rabaul Volcanological Observatory, established after the 1937 disaster, was one of the first permanent volcano monitoring institutions in the Pacific.

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Up to 75 cm of wet volcanic ash accumulated on parts of Rabaul city during the 1994 eruption, collapsing roughly 80% of buildings.

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Tavurvur has been in nearly continuous eruption since 1994, producing activity over two decades.

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The 1937 eruption killed over 500 people, mostly indigenous Tolai communities, because no monitoring system existed.

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Rabaul is one of 16 Decade Volcanoes identified by the IAVCEI for its combination of eruptive potential and proximity to populations.

Frequently Asked Questions

Is Rabaul still active?
Yes, Rabaul is one of the most active volcanic complexes in the southwestern Pacific. The Tavurvur cone within the caldera last erupted in July 2014 and has been in near-continuous activity since the major 1994 eruption. Fumarolic emissions continue, and the caldera's magma system shows ongoing signs of dynamic behavior through ground deformation detected by satellite radar. The Rabaul Volcanological Observatory continuously monitors the caldera for any signs of renewed eruption.
What happened during the 1994 Rabaul eruption?
On September 19, 1994, Vulcan and Tavurvur cones erupted simultaneously inside the Rabaul caldera in a VEI 4 event. The eruption produced powerful explosions, pyroclastic flows, and heavy ashfall that deposited up to 75 cm of ash on parts of Rabaul city. Approximately 80% of the town's structures were damaged or destroyed. However, thanks to decades of monitoring by the Rabaul Volcanological Observatory, evacuation plans were activated quickly, and only five people died out of a population of approximately 30,000 — making it one of the most successful volcanic evacuations in history.
When did Rabaul last erupt?
Rabaul's Tavurvur cone last erupted on July 7, 2014, in a VEI 3 event that produced a significant eruption column and ashfall across the surrounding area. Prior to that, Tavurvur had been in nearly continuous eruption since September 1994, with only brief pauses. The most recent sustained eruptive period ran from 2006 to 2010 at VEI 4. The caldera has experienced some form of eruptive activity in most years since 1994.
How was the 1994 evacuation so successful?
The 1994 evacuation succeeded because of lessons learned from the deadly 1937 eruption, which killed over 500 people. After 1937, the Rabaul Volcanological Observatory was established and developed a comprehensive monitoring network and evacuation plan over decades. Seismic activity, ground uplift, and geochemical changes were tracked continuously. When the eruption began on September 19, 1994, the population was already on alert and evacuation routes were well-practiced. The vast majority of Rabaul's 30,000 residents escaped, with only five fatalities.
What type of volcano is Rabaul?
Rabaul is a caldera volcano — a large volcanic depression formed when a massive eruption emptied an underlying magma chamber, causing the surface to collapse. The Rabaul caldera measures 8 by 14 km and is breached on the east, where Blanche Bay floods the caldera floor. Within this caldera, multiple volcanic cones have grown, most notably Vulcan and Tavurvur. The caldera was formed approximately 1,400 years ago in a VEI 6 eruption and sits within the Bismarck Volcanic Arc, driven by subduction of the Solomon Sea Plate.
Can you visit Rabaul?
Yes, Rabaul is accessible via Tokua Airport near Kokopo, served by flights from Port Moresby. The partially ruined town, Japanese WWII tunnel networks, the Tavurvur cone, and hot springs around Blanche Bay attract visitors. Guided tours to the Tavurvur area offer views of the steaming cone and ash-covered ruins. Blanche Bay also offers diving on WWII wrecks. Accommodation is available in Kokopo, the replacement provincial capital approximately 20 km southeast. Visitors should check volcanic alert levels with the Rabaul Volcanological Observatory before approaching the caldera.
How big is the Rabaul caldera?
The Rabaul caldera measures approximately 8 by 14 km, making it one of the larger active calderas in the Pacific. It is widely breached on its eastern side, where the flooded caldera floor forms Blanche Bay, a deep natural harbor. The outer caldera rim reaches 688 m elevation. For comparison, the Aira caldera containing Kagoshima city in Japan measures 17 by 23 km, while Campi Flegrei near Naples spans about 13 km across.