A ghost island emerges in the Pacific

In the southwestern Pacific Ocean, a submerged mountain range in the seabed that extends from New Zealand until Tonga has the highest density submarine volcanoes of the world. On September 10, one of them woke up. As a consequence, eleven hours after the eruption began, a new island emerged, surrounded by steam and ash, as well as columns of discolored water formed by acidic and superheated seawater that surely contain particles, fragments of volcanic rock and sulfur, according to a report release The NASA.

Slowly, the debris built up on a whole new island, covering 4,000 square meters and reaching a height of 10 meters in just a few days. On September 20, Tonga Geological Survey (TGS) officials announced that the island had increased six times in size, expanding to 24,000 square meters. However, despite being a ‘newborn’, it is not the first time something like this has been observed in the area. It is a kind of ‘ghost island’, which appears and disappears after volcanic eruptions.

Home Reef Seamount

Although technically the island is a new formation, in reality other islands have arisen in the area before. It’s about seamount Homereef, located in the Central Tonga Islands, where from time to time, lava oozes, expelling columns of steam and ash. The material accumulates and, resurfacing like the phoenix, this ephemeral structure rises. However, it will be for a short time, since in all probability it will end up sinking again in the fiery ‘Ring of Fire’ of the Pacific Ocean, eroded by the waves.

The last time Home Reef gave birth to a new island, in 2006, the volcano produced so much debris that a huge raft of pumice rock surfaced and drifted in the South Pacific, giving it the strange appearance of land. However, ships could pass through it. The sea took a year to erode the ridge that had emerged from Home Reef, a formation almost as large as the previous one recorded in 1984, where it reached more than 50 meters and even housed a small lagoon. Previously, other ‘ghost islands’ like this and the current one were sighted in 1852 and 1857.

The underwater volcano responsible for these ephemeral structures is located in a region of the Pacific Ocean known as the Subduction Zone of Tonga-Kermadec, where are some of the tectonic plates convergence most active in the world. Here, the Pacific Plate is continuously and rapidly sliding under two other plates (Kermadec and Tonga) at a rate of about 24 centimeters per year, forming the second deepest trench in the world and an extremely active volcanic arc.

new island

Satellite images of the recent eruption captured the formation of the new island in amazing detail. The image below was released by NASA using data from the US Geological Survey on September 14 and shows not only a long plume of smoke, but also intense discoloration of the surrounding ocean. A follow-up image taken on September 18 with data from the USGS and shared by the TGS on social networks shows its evolution.

“The volcano poses low risks to the aviation community and residents of Vava’u and Ha’apai”TGS announced on September 20. “However, all vessels are advised to sail beyond 4 kilometers away from Home Reef until further notice.”. Since September 25 there have been no further sightings of volcanic ash or steam in this portion of the Pacific. Home Reef is likely done for now, leaving us, for the time being, with its short-lived new ‘ghost island’.

Font: ABC

Reference article: https://www.abc.es/ciencia/emerge-isla-fantasma-pacifico-vista-ultima-2006-20220928191915-nt.html