A submerged volcano in the seamount known as Home Reef in the central islands of Tonga has woken up after 16 years of deep slumber to poke its head out of the blue.
On September 10, 2022, fragments of lava and rock began to sink into the ocean 25 kilometers (15 miles) southwest of Late Island, as plumes of steam and ash erupted across the surface of the waves .
Gradually, the debris gathered into a completely new island, covering 4,000 square meters (one acre) and reaching a height of 10 meters (33 feet) in a few days.
Although it would hardly grow much larger, on September 20 Tonga Geological Survey (TGS) officials announced that the island had swelled six times, expanding to 24,000 square meters.
Like a phoenix rising from the ashes, this nameless, ephemeral structure will likely sink back into the Pacific Ocean’s fiery “Ring of Fire” long before any sailors can hope to set foot on its rocky shore .
The last time Home Reef gave birth to a new island, in 2006, it took a year for ocean waves to erode its crest. This time, the crest is much shorter.
The submerged Tonga volcano produced so much debris in the 2006 event, an expansive pool of frothy volcanic glass known as pumice drifted across the South Pacific, giving the land’s eerie appearance.
You can see the images of this raft below:
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Since 1852, Home Reef has produced islands on five occasions, some of which reach between 50 and 70 meters in height. In 1984, the island even had a small lagoon.
The seamount responsible for these short-lived structures is located in a region of the Pacific Ocean known as the Tonga-Kermadec subduction zone, which contains some of the fastest-converting tectonic plates in the world.
Here, the Pacific plate is sliding rapidly under two other plates (the Kermadec and Tonga) at a rate of about 24 centimeters per year (9 inches), forming the world’s second deepest trench and an extremely active volcanic arc .
In fact, this long stretch of seafloor ridge, stretching from Tonga to New Zealand, is home to the highest density of underwater volcanoes found anywhere on Earth.
Satellite images of Home Reef’s recent eruption capture the formation of its newest island in stunning detail. The image below was released by NASA using data from the US Geological Survey on September 14.
It shows not only a long smoke trail, but an intense discoloration of the surrounding ocean.
A submerged volcano erupting to form Home Reef. (Lauren Dauphin/NASA Earth Observatory/USGS)
A tracking image taken on September 18 using data from the USGS and shared by TGS on Facebook zooms in on the volcanic fallout, as seen below.
The eruption that formed Home Reef in September 2022. (USGS)
The cloudiness of the water is likely the result of superheated acidic seawater mixed with chunks of volcanic rock and debris, according to a recent NASA press release.
“The volcano poses a low risk to the aviation community and residents of Vava’u and Ha’apai,” TGS announced on September 20.
“However, all boaters are advised to sail beyond 4 kilometers of Home Reef until further notice.”
Since September 25, no further volcanic ash or steam has been observed in this part of the Pacific. Home Reef is probably done for now, leaving us to appreciate its latest gift to the sea while we can.