Smoke billows from a new island off the coast of Nishinoshima, a small, uninhabited island in the Ogasawara chain, far south of Tokyo Thursday, Nov. 21, 2013 (Photo: AP)
A dramatic volcanic eruption in the Pacific Ocean has created a tiny new islet in Japan's territorial waters, officials said Thursday, the first time in decades the nation has seen the phenomenon.
The navy spotted smoke about 1,000 kilometres (600 miles) south of Tokyo on Wednesday and Japan's coastguard later verified the birth of the islet around the Ogasawara island chain.
Video footage showed plumes of smoke and ash billowing from the 200-metre island, and Japan's coastguard said it was warning vessels to use caution in the area until the eruption cools off.
"Smoke is still rising from the volcanic island, and we issued a navigation warning to say that this island has emerged with ash falling in the area," said a spokesman for the maritime agency.
He added that the islet may not last long due to erosion, but if enough volcanic lava surfaces and solidifies it could mark a new entry on the map.
Similar eruptions in the early 1970s and mid-80s created tiny islets in Japan's territory that have since been partially or completely eaten up by the ocean.
Japan's top government spokesman joked that he hoped the outcrop would mark an expansion of Tokyo's maritime territory -- a reference to diplomatic rows with China and South Korea over ownership of other islands far from the tiny islet.
"If this becomes a solid island, our country's territorial waters will expand," Chief Cabinet Secretary Yoshihide Suga quipped in response to questions about the new addition.
In September Pakistan also witnessed the birth of a new island -- a mound of mud and rock 20 metres (70 feet) high and 90 metres wide created by a huge earthquake that hit the country's southwest.
The phenomenon on the coastline near the port of Gwadar caused astonishment when it emerged from the Arabian Sea but experts also said it was unlikely to last long.
Video footage of the Japanese islet can be seen here: http://headlines.yahoo.co.jp/videonews/fnn?a=20131120-00000215-fnn-soci