Mark Twain once offered a compelling reason for breaking into real estate: “Buy land — they’re not making it anymore.”
Clearly, Samuel Clemens hadn’t considered that Earth’s plate tectonics continues to alter the planet’s geography.
An underwater volcano in the South Pacific erupted in early September, sending lava and gas spewing to the surface of the ocean. It only took 11 hours for the volcano to create a new island visible from space.
The island continued to grow quickly this month. Located in the Central Tonga Islands between Tonga and New Zealand, it had risen about 15 metres above the water by September 19, Tonga Geological Services (TGS) reported.
As of last week, it measured 211m from north to south and about 218m from east to west. The new island covered about 3.5 hectares, TGS said.
That area of the seafloor has the world’s highest density of underwater volcanoes, according to NASA. Those volcanoes led to the creation of many of Tonga’s 170 islands.
Will the island last?
Nothing lasts forever, and that’s especially true of volcanic islands.
This latest addition to the Tonga islands isn’t solid ground yet, but rather a collection of rock fragments and ash that combines with the cooling lava to form an island.
“It’s more like a large layer of ash, steam, and pumice over the ocean,” Rennie Vaiomounga, a geologist at the Tonga Geological Services, told The Washington Post.
The island rose up from Tonga’s Home Reef, which has produced several new islands over the last 150 years. The Home Reef sits within the Tonga-Kermadec subduction zone, an area where three rapidly converging tectonic plates are colliding.
As a result, volcanic eruptions in the Home Reef in 1852, 1857, 1984, and 2006 all resulted in new land masses, NPR reported.
Unfortunately, all those islands eventually sank back into the ocean. Waves erode the volcanic rock away, slowly breaking down the islands into nothing. The island that rose up in 2006 had vanished back into the ocean within two years.
Yet some islands do survive. A 2014 eruption created an island that not only remains above the ocean, but now hosts plants and birds, IFL Science reported.
Who’s to say whether this latest island will stand the test of time?
Contrary to Twain, the Earth still makes new land — but it can also decide to take it back.
