New Pacific Ocean Island Spotted After Underwater Volcanic Eruption

An undersea volcano is seen erupting off the coast of Tonga, sending plumes of steam, ash, and smoke up to 100 meters into the air on March 18, 2009. (Dana Stephenson/Getty Images)

A new island has emerged in the southwest Pacific Ocean after an underwater volcano erupted near Tonga, although its existence may only be transitory, according to NASA’s Earth Observatory.

The Home Reef volcano in the Central Tonga Islands began to erupt on Sept. 10, oozing lava, emitting steam and ash, and discoloring the surrounding water. NASA stated that the new island was formed 11 hours later.

On Sept. 14, Tonga Geological Services estimated that the island was 4,000 square meters (equivalent to one acre) and 10 meters above sea level. It grew to 24,000 square meters (six acres) six days later, according to NASA.

The agency reported that Home Reef has seen four eruptions, including events in 1852, 1857, and 1984, which resulted in the formation of new islands each time.

Islands formed by undersea volcanoes are often short-lived, although sometimes they persist for years, according to NASA.

“An island created by a 12-day eruption from nearby Late’iki volcano in 2020 washed away after two months, while an earlier island created in 1995 by the same volcano remained for 25 years,” the agency stated.

The new island is located northeast of Hunga Tonga-Hunga Ha'apai, while Home Reef sits within “an area where three tectonic plates are colliding at the fastest converging boundary in the world.”

According to Tonga Geological Services, the new island expanded to 8.6 acres and 49 feet above sea level as of Sept. 19, with volcanic activities at Home Reef seamount continuing on the 16th day.

The geological agency stated on Sept. 26 that there were 13 eruptions of the Home Reef volcano in the previous 24 hours, but noted that they posed a low risk to the local communities in Vava‘u and Ha’apai islands.

“All mariners are advised to sail beyond 4km [2.5 miles] from Home Reef until further notice,” the Tonga Geological Services said in a statement posted on Facebook.

Tonga was hit by an underwater eruption of the Hunga Tonga-Hunga Ha’apai volcano and a subsequent tsunami on Jan. 15 that wiped out an entire village on one of Tonga’s small outer islands and killed at least three people.

Scientists said the Tonga volcanic eruption in January was the largest atmospheric explosion documented since the 1883 Krakatoa eruption in Indonesia.