According to an upcoming report from the Geospatial Information Authority of Japan, the number of islands that make up the archipelago has increased from the 6,852 in a 1987 survey to the current total of 14,125.

The doubling in the number of islands is the result of many factors. Volcanic activity has indeed led to the creation of new islands. But the more mundane fact is that the change is mainly due to advances in mapping technology since the Japan Coast Guard carried out its previous survey 35 years ago. There’s also the fact that the 1987 survey only included islands with a circumference of at least 100 meters and excluded many islands in lakes and rivers.

Of the 7,000+ new islands, 1,479 are located off Nagasaki Prefecture in the south of Kyushu, one of Japan’s “big 4” islands. Tokyo has been encouraging local governments to give formal names to the many previously unidentified islands.

None of the new additions are located in the East China Sea, a region where territorial waters around the Senkaku Islands are increasingly contested by the Chinese authorities.

The GIAJ report is expected to be issued in March.