A new 6-acre island has emerged in the Pacific Ocean

Thanks to the eruption of an underwater volcano.
Ayesha Gulzar
Satellite image shows the Home Reef volcano in Tonga.
Satellite image shows the Home Reef volcano in Tonga.


According to NASA's Earth Observatory, a new baby island emerged after the eruption of an underwater volcano in the Central Islands of Tonga. The island continues to grow, spewing molten lava, steam, and ash at least 1.8 miles (3 kilometers) into the air.

The world's largest underwater volcano concentration is in the southwest Pacific Ocean along a seafloor ridge that runs from New Zealand to Tonga. On September 10, 2022, one of them erupted.

Since then, the Home Reef seamount has repeatedly released ash and steam plumes, oozed lava, and discolored the surrounding water. Eleven hours after the eruption, a new island emerged above the water's surface.

The formation of the island was captured through imagery taken by the Landsat 9 satellite on September 14. A vast plume of steam and ash drifts away from the volcano in the image. Previous studies suggest that these superheated, acidic seawater plumes contain sulfur, volcanic rock fragments, and particulate debris.

The baby island continues to grow

Volcanoes that are submerged in water are known as seamounts. When underwater volcanoes erupt, the lava erupts to form an undersea ridge. Layers of lava build until a ridge breaks the sea's surface to form an island.

Initially, Tonga Geological Services experts estimated the baby island to be 4,000 square meters (1 acre) in size and 13 feet (10 meters) above sea level. However, it had grown to 24,000 square meters (6 acres) by September 20.

"The volcano activity poses low risks to the Aviation Community and the residents of Vava'u and Ha'apai," said Tonga Geological Services. "No visible ash in the past 24 hours was reported. All Mariners are advised to sail beyond 4km away from Home Reef until further notice." The service noted that most ash should fall within a mile or so of the vent.

The new island can be found southwest of Late Island, northeast of Hunga Tonga-Hunga Ha'apai, and northwest of Mo'unga'one. This part is known as the Tonga-Kermadec subduction zone, where three tectonic plates collide at the fastest global converging boundary. The Pacific Plate here is sinking beneath two other small plates, yielding one of Earth's deepest trenches and most active volcanic arcs.

Home Reef has had four recorded periods of eruptions, including events in 1852 and 1857. Small islands temporarily formed after both events, and eruptions in 1984 and 2006 produced ephemeral islands with cliffs that were 50 to 70 meters (31 to 43 km) high.

Unfortunately, the new baby island may cease to exist due to volcanic rock degradation caused by the erosion of the waves. According to NASA, islands created by submarine volcanoes are often short-lived, though they occasionally persist for years. For example, an island formed by a 12-day eruption from nearby Late'iki Volcano in 2020 washed away after two months, while an island created in 1995 by the same volcano remained for over two decades.

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