Japan got just a little bit bigger this week, as a volcano created abrand new island about 600 miles (970 kilometers) south of Tokyo.

The island is about 660 feet (200 meters) in diameter, according to the Japanese coast guard. It sits off the coast of Nishinoshima, itself a small, uninhabited island in a group of about 30 islands known as the Bonin Islands, or the Ogasawara chain.

Asked by the media if the new island will soon get a name, Japanese government spokesperson Yoshihide Suga replied that officials will first wait to see how long it sticks around, since new islands have a tendency to disappear back below the waves in a short time. (Related: "How Did the Pakistan Earthquake Create a Mud Island?")

"If it becomes a full-fledged island, we would be happy to have more territory," Suga told the press.

On Thursday, the Japanese coast guard released video of the new island, forged under billowing smoke and steam. The video shows ash and rocks exploding from a crater that erupted from the sea.

A coast card volcanologist, Hiroshi Ito, told FNN news that it's unclear if the island will become permanent or get reclaimed by the sea.

Japan is an archipelago of thousands of islands, though most of the nation's people live on a few of the largest ones. Japan is well known for volcanic activity and earthquakes, and it is perched on the Ring of Fire, a fringe of coastline that surrounds much of the Pacific Ocean.

The tectonically active region includes coastal eastern Asia and long stretches of western North and South America. It is the Ring of Fire that fueled last century's big eruptions at Mount St. Helens in Washington State and Mount Pinatubo in the Philippines.

The volcanoes that built Japan's newest island last erupted in the mid-1970s, along the Izu-Ogasawara-Mariana Trench.