A new island has appeared in the southwestern Pacific Ocean as the Home Reef seamount in the Central Tonga Islands erupted, starting along a volcanic ridge that traces from New Zealand down toward the seafloor. This eruption has created a site with an unusually dense concentration of submarine volcanoes and has heightened the region’s volcanic activity. Since the first eruptions, Home Seamount has intermittently released lava, vented steam and ash, and altered the color of the surrounding water with discoloration.
Eleven hours after the eruption began, a landmass finally broke the water’s surface. The Operational Terrain Imager-2 (OLI-2) on NASA’s Landsat 9 satellite captured a natural color image of this young island on its first day, while earlier research indicated that the intense, acidic seawater contained volcanic particulates, rock fragments, and bits of sulfur, as reported by Europa Press with reference to NASA Earth Observatory.
By September 14, researchers from the Tonga Geological Survey estimated the island’s area at about 4,000 square meters and its elevation above sea level near 10 meters. By September 20, the landmass expanded to roughly 24,000 square meters. The new island lies southwest of Late Island, northeast of Hunga Tonga-Hunga Ha’apai, and northwest of Mo’unga’one, in proximity to a year marked by one of the planet’s most violent volcanic events. This growing feature sits in the path of an active volcanic arc that has repeatedly reshaped the landscape in this region.
Home Reef lies within the Tonga-Kermadec Subduction Zone, a zone where three tectonic plates converge along the world’s fastest-moving boundary. Here, the Pacific Plate dives beneath two smaller plates, creating one of the deepest ocean trenches and a highly active volcanic chain that has long fascinated scientists for its dynamic geology.
Islands birthed by submarine eruptions are typically short-lived, sometimes persisting for only a few years. Home Reef has had four documented eruption periods, including events recorded in 1852 and 1857. In the aftermath of those eruptions, small islands formed briefly, and the 1984 and 2006 eruptions produced ephemeral landmasses with cliffs ranging from 50 to 70 meters in height. The nearby Late’iki volcano produced a temporary island after a 12-day eruption in 2020, which disappeared after two months, while another landmass from a 1995 eruption persisted for about 25 years.
The Tonga Geological Survey noted in an update on September 20 that the volcano poses a low risk to aviation and to residents of Vava’u and Ha’apai. Nevertheless, vessels are advised to stay more than 4 kilometers from Home Reef until further notice, as most ashfall tends to settle within a few kilometers of the vent. Such guidance helps maritime traffic avoid ash clouds, turbulences, and potential engine damage from volcanic debris.
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