Gaua

Gaua has erupted 18 times since 1962, averaging one eruption every 3–4 years — making it one of the most frequently active volcanoes in the southwestern Pacific.

Lake Letas, the crescent-shaped crater lake within Gaua's caldera, is the largest lake in Vanuatu with a surface area of approximately 5 km².

The island's population of approximately 2,500–3,000 subsistence farmers has been periodically evacuated due to volcanic ashfall that destroys food gardens — their primary food source.

Gaua's 6 × 9 km summit caldera was formed by quiet collapse rather than a single catastrophic eruption, unlike many calderas around the world.

Mount Garet, the active cone within the caldera, has three pit craters across its summit and has been the source of all recorded eruptions.

The island was dormant for an unknown period before 1962, when eruptions resumed and have continued intermittently ever since.

Gaua is known for its unique cultural practice of water music, where women create rhythmic sounds by slapping the ocean surface — a tradition recognized by UNESCO.

Volcanic acid rain from SO₂ emissions during eruptions corrodes metal roofing and contaminates rainwater collection systems — the island's primary water source.

The Vanuatu volcanic arc, of which Gaua is part, contains approximately 12 historically active volcanic islands along the New Hebrides Trench subduction zone.

Gaua's remoteness means eruption response depends heavily on small aircraft and inter-island boats — evacuation during bad weather can be extremely difficult.

Littoral cones formed where Pleistocene lava flows from caldera-rim vents reached the ocean, creating distinctive coastal formations around the island.

In 2009–2010, heavy ashfall from Mount Garet severely damaged the island's food supply, requiring international humanitarian assistance for the community.