The land area of Nishinoshima island, part of the Ogasawara Islands belonging to Tokyo, has reached about 2.57 square kilometers due to a series of volcanic eruptions, the Japan Coast Guard announced on Friday.
Now 55 times as large as Tokyo Dome, the land has expanded by 0.12 square kilometers since it was last observed in March, according to the JCG. It added the island will possibly see further outflows of lava on larger scales as volcanic activity is still under way.
Through an observation from a JCG aircraft on Wednesday afternoon, it confirmed active eruptions from the island's crater at intervals of two to three times a minute, as well as an outflow of lava at its southeastern beach.
In an area of the sea about 10 kilometers southwest of the island, the water was observed to have turned a yellowish green partly due to volcanic gas rising from the bottom of the sea. An increase in magma beneath the seafloor is also considered a possible reason, a JCG official said.
There was a major outflow of lava last September, during which the island rapidly grew, and the colour of the seawater about 10 kilometers south of the island changed. The JCG says a similar event could happen again.