Japan Data

Japan’s Islands Double to 14,125 Following New Survey


The number of islands forming the Japanese archipelago has dramatically doubled to 14,125. Rather than the discovery of new islands, this is due to advances in surveying technology, based on aerial photography, for a more accurate count.

Japan is made up of many islands. Up to now, it was thought there were 6,852, based on a 1987 Japan Coast Guard report. However, when the Geospatial Information Authority of Japan recounted them recently for the first time in 36 years, the figure came to more than double that with 14,125.

Using data from the Digital Japan Basic Maps, which are the basis for 1:25,000 scale topographic maps, a count was conducted of naturally formed islands with a coastline of 100 meters or more in length. Artificial islands created through land reclamation or other means were excluded. The sharp rise in the number of islands was mainly due to advances in surveying technology, including aerial photography, making it possible to get a clearer picture of complex coastlines, and identify islands that had not been counted as they were thought to be connected to land or cases where two separate islands were thought to be one. Thus, although the number has increased, this has not affected Japan’s national territory as the new islands were already recognized as Japanese land.

By prefecture, Nagasaki has the most islands with 1,479, including Iki, Tsushima, and the Gotō Islands. Hokkaidō comes a close second with 1,473 islands, followed by Kagoshima with 1,256. Tokyo’s administrative powers extend to both the Izu and Ogasawara Islands, so it ranks eighth with 635 islands.

Japanese Prefectures with the Most Islands

(Translated from Japanese. Banner photo © Pixta.)

geography islands