🌋VolcanoAtlas

Ambrym

Vanuatu's Black Island — Home of Persistent Lava Lakes

Elevation

1,334 m

Last Eruption

2024

Type

Shield (pyroclastic)

Country

Vanuatu

Location

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Volcanic Hazards & Risk Assessment

Primary Hazards

  • Lava flows and fountaining
  • Volcanic gas emissions
  • Local explosive activity

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 Activity2 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 Vanuatu Volcanoes
Explore by country
Shield (pyroclastic) Volcanoes
By volcano type
Malampa Province, Vanuatu Volcanic Arc
Regional volcanoes

Other Volcanoes in Vanuatu

Interesting Facts

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Ambrym's ~50 AD caldera-forming eruption was one of the largest volcanic events in the Pacific in the last 2,000 years, ejecting an estimated 30+ km³ of material and creating a 12-km-wide caldera.

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Ambrym's lava lakes at Marum and Benbow craters (active ~1950–2018) made it one of only four to six volcanoes on Earth with sustained lava lake activity, alongside Nyiragongo, Kīlauea, Erebus, and Erta Ale.

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During active lava lake periods, Ambrym's SO₂ emissions frequently exceeded 10,000 tonnes per day, making it one of the single largest volcanic point sources of sulfur dioxide on the planet.

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Ambrym Island is known as 'the Black Island' due to the vast expanses of dark volcanic ash and basaltic rock that cover much of its surface, particularly the stark caldera floor.

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With 58 recorded eruptions since ~50 AD, Ambrym averages one eruption approximately every 4.4 years during the historical period — and near-annually since 1950.

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Ambrym's sand drawings, created by tracing continuous geometric patterns in volcanic sand, are recognized by UNESCO as an Intangible Cultural Heritage of Humanity.

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The December 2018 eruption drained Ambrym's long-lived lava lakes within hours as magma diverted laterally into a rift zone, causing ground uplift of over 1 m on the eastern coast.

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The VEI 6 caldera-forming eruption ~50 AD was unusual for Ambrym: it produced dacitic pyroclastic flows, while virtually all other eruptions have been basaltic — an abrupt compositional shift that intrigues volcanologists.

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Ambrym's caldera floor, approximately 12 km wide, is one of the largest and most accessible active volcanic calderas in the world, reachable by a trek from rim villages.

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Acid rain from Ambrym's chronic volcanic degassing has caused widespread crop damage across the island and neighboring islands, significantly impacting food security for island communities.

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The 1950–1951 eruption from Benbow crater (VEI 4) was the most powerful historical eruption at Ambrym and remains the benchmark for hazard planning.

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Ambrym's persistent volcanic glow, visible at night from neighboring islands, has shaped local mythology and cultural traditions for millennia.

Frequently Asked Questions

Is Ambrym Volcano still active?
Yes, Ambrym is one of the most persistently active volcanoes on Earth. It has produced 58 recorded eruptions since ~50 AD, with near-continuous activity since 1950. The most recent eruption occurred in 2024. From approximately 1950 to 2018, Ambrym hosted spectacular persistent lava lakes in the Marum and Benbow craters. Though the lava lakes drained during a dramatic rift intrusion event in December 2018, the volcano continues to produce intermittent eruptions, emit substantial quantities of SO₂ gas, and generate seismic activity. The Vanuatu Meteorology and Geo-Hazards Department monitors the volcano continuously and considers further eruptions virtually certain.
Does Ambrym have a lava lake?
Ambrym hosted two of the world's most spectacular persistent lava lakes — in the Marum and Benbow craters — from approximately 1950 to December 2018. These incandescent basaltic lava pools, typically 30–100 m in diameter, glowed continuously and were a major draw for extreme volcano tourism. In December 2018, both lava lakes abruptly drained when magma diverted laterally into a rift zone on the eastern flank. As of early 2025, the lava lakes have not fully re-established, though intermittent incandescence and minor eruptive activity at both craters have been observed. Scientists expect the lava lakes will eventually return, as they have repeatedly re-established after previous drainage events.
When did Ambrym last erupt?
Ambrym's most recent eruptions occurred in 2024: a VEI 0 eruption in January and an uncertain eruption in October. Prior to that, a VEI 1 eruption occurred at Benbow crater in January 2022. The most significant recent event was the December 2018 eruption, which drained the long-lived Marum and Benbow lava lakes when magma diverted into a lateral rift zone, causing ground deformation and damage to eastern coastal villages. Ambrym has erupted 58 times since ~50 AD and has been in a state of near-continuous unrest since at least 1950.
How big is Ambrym's caldera?
Ambrym's summit caldera is approximately 12 km (7.5 mi) wide, making it one of the largest active volcanic calderas in the southwestern Pacific. The caldera was formed by a catastrophic VEI 6 eruption around 50 AD that produced massive dacitic pyroclastic flows. The caldera floor is a vast, ash-covered depression 200–400 m below the rim, dotted with active craters (Marum, Benbow, Mbuelesu, Niri Taten), lava flows, and cinder cones. For scale, Ambrym's caldera is comparable in diameter to the famous Ngorongoro Crater in Tanzania, though the geological origins are entirely different.
Can you visit Ambrym Volcano?
Yes, when volcanic alert levels permit, Ambrym is one of the world's most rewarding (and challenging) volcano destinations. The signature experience is a guided trek from rim villages such as Endu or Lalinda across the caldera floor to the rim of Marum or Benbow crater — a round trip of typically 4–8 hours across barren ash fields. During lava lake periods, visitors could witness molten basalt from the crater rim. Access is by domestic flight from Port Vila to Craig Cove or Ulei airstrip, or by inter-island boat. Basic guesthouse accommodation is available in villages. A local guide is required and supports the island economy. Always check current VMGD alert levels and respect custom landowner permissions.
What type of volcano is Ambrym?
Ambrym is classified as a basaltic shield volcano with a pyroclastic caldera — an unusual combination. Shield volcanoes are typically broad, gently sloping structures built by fluid lava flows, and Ambrym's pre-caldera form fits this description. However, the massive VEI 6 caldera-forming eruption around 50 AD produced explosive dacitic pyroclastic flows more characteristic of stratovolcanoes, creating the 12-km-wide caldera. Post-caldera activity has reverted to basaltic eruptions, producing lava lakes, Strombolian explosions, and lava flows from Marum, Benbow, and flank vents.
How does Ambrym affect the local population?
Approximately 7,000–10,000 people live on Ambrym Island and face multiple volcanic hazards. The most pervasive ongoing impact is chronic volcanic gas emissions: Ambrym's SO₂ output creates acid rain that damages crops (particularly taro, yam, and coconut), corrodes roofing materials, and causes respiratory health issues. During eruptions, ashfall contaminates water supplies and damages vegetation. The 2018 rift intrusion caused ground deformation and cracking that damaged villages on the eastern coast, displacing thousands. Lava flows from larger eruptions have historically reached the coast and destroyed settlements. Despite these hazards, the island's communities maintain a resilient relationship with their volcano, sustained by cultural traditions and fertile volcanic soils.
Why does Ambrym release so much SO₂?
Ambrym's extraordinary SO₂ emissions — frequently exceeding 5,000–10,000 tonnes per day during active periods — result from its basaltic magma composition and persistent shallow magma supply. Basaltic magmas are relatively sulfur-rich compared to more silicic compositions, and the continuous convection of fresh, gas-rich basaltic magma into the shallow Marum and Benbow craters allows efficient degassing without necessarily producing eruptions. This process is similar to what occurs at other prolific degassing volcanoes like Kīlauea and Etna. The open-vent nature of Ambrym's lava lakes provides a direct conduit from the magma reservoir to the atmosphere, enabling continuous passive degassing at rates that rival or exceed most other volcanoes on Earth.