An estimated 7.9 million cu. meters of lava has gushed out of the seabed to form the new landmass that has since merged with Nishinoshima Island — enough to fill Tokyo Dome six times, the Geospatial Information Authority of Japan says.
The GIAJ made the estimate by comparing aerial images of the merged island about 1,000 km south of Tokyo taken on Feb. 16 and Dec. 17.
What they found was that the approximately 800,000 cu. meters of lava they originally saw had expanded nearly tenfold in just two months, officials said.
The highest point on the merged island is now 66 meters, or 27 meters higher than in December, they said.
The new island is continuing to expand. Its existence was confirmed in November.