Volcanoes in Vanuatu

Vanuatu has 12 Holocene volcanoes distributed across this South Pacific archipelago of roughly 80 islands, forming one of the most volcanically active nations on Earth relative to its size and population. The volcanic chain follows the New Hebrides Volcanic Arc, a 1,200-km-long island arc generated by the subduction of the Australian Plate beneath the Pacific Plate (or the New Hebrides microplate) at the New Hebrides Trench. For a nation of only approximately 320,000 people, Vanuatu's volcanic activity is remarkably intense: at least 5–6 volcanoes are regularly active, and the country has logged 145 confirmed eruptions in the geological record.

The crown jewel of Vanuatu's volcanism is [[volcano:yasur|Yasur]] on Tanna Island — one of the most accessible active volcanoes on Earth and arguably the world's most continuously active volcano. Yasur has exhibited essentially continuous Strombolian and Vulcanian activity since at least Captain James Cook observed ash eruptions from its crater in 1774, and oral traditions suggest activity stretching back over 800 years. Alongside Yasur, [[volcano:ambrym|Ambrym]] ranks as one of the most powerful volcanic systems in the Pacific, with 56 confirmed eruptions including a VEI 6 caldera-forming event approximately 2,000 years ago and persistent lava lake activity that places it among the most volcanically productive islands on the planet.

[[volcano:ambae|Ambae]] (also known as Aoba), the highest point in Vanuatu at 1,496 m (4,908 ft), erupted significantly in 2017–2018, forcing the temporary evacuation of the island's entire population of approximately 10,000 people — one of the most dramatic volcanic evacuations in modern Pacific history. [[volcano:lopevi|Lopevi]], an uninhabited conical stratovolcano, erupted most recently in 2007. The country's volcanic hazards are compounded by its low-lying coastal populations, limited infrastructure, and vulnerability to cyclones, making Vanuatu one of the most disaster-prone nations in the world. Monitoring is provided by the Vanuatu Meteorology and Geohazards Department (VMGD).

Vanuatu's volcanism is generated by the subduction of the Australian Plate beneath the Pacific Plate (or more precisely, the New Hebrides microplate) at the New Hebrides Trench, located west of the island chain. The Australian Plate descends eastward at approximately 9–12 cm per year — one of the fastest subduction rates on Earth — creating a vigorous magma supply that sustains the high level of volcanic activity across the archipelago.

The New Hebrides Volcanic Arc extends over 1,200 km from the Santa Cruz Islands (Solomon Islands) in the north to the submarine Hunter Ridge in the south. Vanuatu occupies the central portion of this arc. The subducting slab descends through intermediate-thickness oceanic crust (15–25 km), generating predominantly basaltic to andesitic magmas that produce a range of eruption styles from persistent Strombolian activity (Yasur) to major caldera-forming explosions (Ambrym).

The arc's tectonic setting is complicated by the collision of the d'Entrecasteaux Ridge, an aseismic ridge on the subducting Australian Plate, with the arc in the central Vanuatu region. This collision causes uplift, back-arc spreading, and modifications to the volcanic plumbing system that may contribute to the exceptional activity of volcanoes like Ambrym and Ambae. The [[special:ring-of-fire|Ring of Fire]] extends through Vanuatu as part of the western Pacific's most active subduction belt.

**Yasur** — [[volcano:yasur|Yasur]] on Tanna Island is Vanuatu's most famous volcano and one of the most accessible active volcanoes on Earth. Rising to just 361 m (1,184 ft), this small [[special:types-of-volcanoes|stratovolcano]] has been in near-continuous Strombolian and Vulcanian eruption for at least 800 years — possibly much longer. Captain James Cook was guided to Tanna in 1774 by the glow of Yasur's eruptions visible far out to sea.

Today, visitors can walk to the crater rim (a 15-minute trek from the car park) and watch explosive bursts of incandescent lava bombs every few minutes, making it one of the most dramatic volcano viewing experiences anywhere on Earth. The volcano is deeply sacred to the indigenous Tannese people and plays a central role in local custom and the John Frum cargo cult.

**Ambrym** — [[volcano:ambrym|Ambrym]] is Vanuatu's most powerful volcano and one of the most volcanically active islands in the Pacific. This large basaltic shield-pyroclastic volcano features a 12-km-wide caldera formed during a major VEI 6 Plinian eruption approximately 50 CE — one of the largest eruptions in the South Pacific in the past 2,000 years. With 56 confirmed eruptions, Ambrym has hosted persistent lava lakes in its Marum and Benbow craters and produces prodigious volumes of volcanic SO₂ gas — at times ranking among the world's top volcanic gas emitters.

A major eruption in December 2018 caused a rift zone intrusion that produced submarine lava flows and triggered significant ground deformation across the island.

**Ambae (Aoba)** — [[volcano:ambae|Ambae]] is the highest point in Vanuatu at 1,496 m (4,908 ft) and the most voluminous volcano in the archipelago, with an estimated volume of 2,500 km³. This massive basaltic shield volcano contains a summit caldera with a crater lake (Lake Voui). In 2017–2018, explosive eruptions from the summit lake generated lahars and heavy ashfall that devastated crops and contaminated water supplies, leading to the evacuation of the island's entire population of ~10,000 people.

The volcano had 12 confirmed eruptions and was active in 2025.

**Lopevi** — [[volcano:lopevi|Lopevi]] (Vanei Vollohulu) is a steep, symmetrical 7-km-wide conical island that is one of Vanuatu's most active volcanoes with 30 confirmed eruptions. The island was permanently evacuated in the 1960s due to volcanic hazards and remains uninhabited. Lopevi last erupted in 2007.

**Gaua** — [[volcano:gaua|Gaua]] (Santa Maria) is a 20-km-diameter island volcano with 18 confirmed eruptions. Its summit caldera contains Lake Letas, the largest lake in Vanuatu. Gaua's most recent eruption was in 2022.

**Kuwae** — [[volcano:kuwae|Kuwae]] is a largely submarine caldera between Epi and Tongoa islands. Some researchers have proposed that a massive eruption at Kuwae around 1452–1453 CE may have been one of the largest eruptions of the past millennium, though this dating and magnitude remain debated. The 6 × 12 km caldera contains submarine cones, and the system has 12 confirmed eruptions.

Vanuatu's volcanic record includes 145 confirmed eruptions across its 12 Holocene systems, with an intensity of activity that belies the country's small size. The most catastrophic event was the VEI 6 caldera-forming eruption of [[volcano:ambrym|Ambrym]] around 50 CE, which produced dacitic pyroclastic flows and created the 12-km-wide caldera that dominates the island today. This eruption deposited thick ignimbrite layers across the island and into the surrounding sea.

The proposed massive eruption of Kuwae (c. 1452–1453 CE) has been the subject of significant scientific debate. If confirmed at its proposed VEI 6+ magnitude, it would rank among the largest eruptions of the past millennium, potentially contributing to global cooling in the mid-15th century. However, recent research has questioned the magnitude and dating, and the eruption's exact scale remains uncertain.

In the modern record, [[volcano:yasur|Yasur]]'s continuous activity has made it a living volcanic laboratory. [[volcano:ambrym|Ambrym]]'s persistent lava lakes and frequent eruptions (VEI 2–4) have made it one of the most volcanically productive islands on Earth. The 2017–2018 Ambae eruptions forced the temporary evacuation of the entire island population — a logistically extraordinary event for a small Pacific nation — and demonstrated the acute vulnerability of Vanuatu's island communities to volcanic hazards.

The VEI distribution for Vanuatu shows 86 eruptions at VEI 2, 21 at VEI 3, 1 at VEI 4, and 1 at VEI 6, with the majority of activity being moderate but persistently frequent.

Vanuatu faces acute volcanic hazards amplified by geographic isolation, limited infrastructure, and the proximity of communities to active vents. Ashfall is the most widespread hazard, damaging crops, contaminating water supplies, and affecting air quality across populated islands. The 2017–2018 Ambae eruptions demonstrated how quickly volcanic activity can render an entire island temporarily uninhabitable.

Lava flows from Ambrym, Lopevi, and Yasur threaten coastal communities. Volcanic gas emissions — particularly SO₂ from Ambrym, which ranks among the world's top volcanic SO₂ sources — cause chronic acid rain, vegetation damage, and respiratory health issues on downwind islands. Pyroclastic flows from explosive eruptions at calderas (Ambrym, Kuwae) could be catastrophic.

Volcanic tsunamis from submarine eruptions or sector collapses represent an additional threat to Vanuatu's low-lying coastal settlements.

The Vanuatu Meteorology and Geohazards Department (VMGD) maintains monitoring on key volcanoes including Yasur, Ambrym, and Ambae, with support from international partners including GNS Science (New Zealand) and the U.S. Geological Survey. However, the country's dispersed geography and limited resources make comprehensive monitoring challenging.

Vanuatu's 12 volcanoes are distributed across approximately 800 km of the New Hebrides Arc, from Motlav in the northern Banks Islands (13.7°S) to the submarine Gemini-Oscostar volcanic field in the south (21°S). The chain broadly parallels the New Hebrides Trench to the west.

The northern Banks Islands contain Motlav, Suretamatai, and Gaua. The central group — Ambae, Ambrym, Lopevi, East Epi, and Kuwae — represents the most active segment. The southern islands include Nguna-Emau (near Efaté, the capital island), Traitor's Head (Erromango), and Yasur (Tanna).

Gemini-Oscostar lies at the submarine southern terminus of the arc.

Volcanoes are deeply woven into Ni-Vanuatu (indigenous Vanuatu) culture and spirituality. Yasur on Tanna is sacred to the indigenous population and central to local custom traditions, including the John Frum cargo cult, whose followers revere the volcano. Ambrym's volcanic landscapes have inspired the island's renowned tradition of sand drawing, recognized by UNESCO as an Intangible Cultural Heritage.

Volcanic tourism is a growing economic contributor, with Yasur being Vanuatu's most visited natural attraction. The volcano's accessibility and dramatic eruptions draw thousands of visitors annually. Volcanic soils support agriculture on several islands, though ashfall from active volcanoes periodically devastates crops — as occurred during the 2017–2018 Ambae eruptions.

The geothermal potential of Vanuatu's volcanoes remains largely untapped, representing a significant future energy opportunity.

[[volcano:yasur|Yasur]] on Tanna Island is one of the world's most accessible and spectacular volcano experiences. Visitors fly from Port Vila to Tanna, then drive to the volcano's base, where a 15-minute walk leads to the crater rim. From there, explosive Strombolian eruptions hurl incandescent lava bombs every few minutes — visible from just meters away.

Evening visits offer the most dramatic viewing. Local guides are required, and visitors should check VMGD alert levels before visiting.

Ambrym was historically accessible for adventurous volcano trekkers wanting to view its lava lakes, though the 2018 eruption significantly altered the summit calderas and access has been variable since. Ambae's summit crater lake can be reached by guided trek. Domestic flights from Port Vila connect to Tanna, Ambrym, and other volcanic islands.

The dry season (May–October) offers the best travel conditions, though Yasur is accessible year-round.