White smoke plumes above Metis Shoal observed this week.
White smoke plumes above Metis Shoal observed this week.
Massive plumes of white smoke are rising kilometres over a remote spot in the Pacific after an underwater volcano erupted earlier this week, and it could potentially mean the arrival of a brand new island.

The eruption at Matis Shoal, a submarine volcano around halfway between the islands of Kao and Late in Tonga, was first noticed on Tuesday when a pilot with the Real Tonga airline flew over the area and alerted ground control to white columns of steam rising to about 5000 metres elevation.

GeoNet and the Wellington Volcanic Ash Advisory Centre, a department of Metservice, have been monitoring the situation, but say there is currently no risk to flights in the area.

"There's no volcanic ash, just steam and smoke," Metservice meteorologist Tamara Vuksa said. "We only warn airmen about ash, so we've put out a notice to inform people, but there's no need to issue flight warnings."

The island erupted earlier this year in August, which send massive swatchs of floating pumis spreading across the area. One sailor said they spend 6-8 hours sailing through the 15cm thick pumis without ever seeing water.

Matis Shoal has erupted a number of times previously, and is notable for sometimes creating temporary volcanic islands. Eruptions were noted in 1967 and again in 1979, when an island formed which which names Lateiki and officially recognised by the Tongan government. It was an ugly, black lump of rock, which dissolved back into the ocean within a few months.

In 1995, the island appeared again after another eruption, with a 280m diameter and a height of 43m, before again disappearing, though a small portion was observed again in 2006. There are also recordings of islands appearing in the area in area in 1781 and 1854. Geologists are watching closely to see whether that will happen again.