TOKYO: The number of listed islands in Japan has more than doubled to 14,125 under a recount, compared to the 6,852 last tallied around 35 years ago, a government agency said on Tuesday.
The increase does not change the size of Japan's territory or territorial waters and the new figure is due to the improved accuracy of survey technology with the digitisation of maps, said the Geospatial Information Authority of Japan (GSI).
Until now, the government had been using the number released in 1987 by the Japan Coast Guard, which had manually counted islands with a circumference of at least 100 metres shown on a map of the country.
Moves to reassess the number of listed islands followed criticism that the data was old. The new figure could affect entries in educational and other materials.
For the recount, the GSI said it had selected islands that had a circumference of at least 100 metres and that were judged to be naturally formed, among the 120,729 islands automatically measured by computers based on the agency’s electronic national land map.
The islands were cross-checked against past maps to exclude artificially created reclaimed land.
The uninhabited Okinotori Island, regarded by Japan as its southernmost territory but by Taiwan as a rock, is included along with other islands under Japanese law.
Islands in lakes and river channels are not included.
The GSI, under the land ministry, said it defined islands in line with the United Nations Convention on the Law of the Sea, which states that an island is a "naturally formed area of land, surrounded by water, which is above water at high tide”.
