Japan Unveils Discovery of Over 7,000 Hidden Islands

A recent survey uncovered that Japan has more than double the number of islands than previously accounted for.

Recently, the Geospatial Information Authority of Japan (GSI) identified 7,273 new islands, while the archipelago was believed to have 6,852 islands based on a 1987 report by the Japan Coast Guard.

(The GSI technically detected 100,000 islands, but only those with a circumference of at least 330 feet were officially counted.)

However, this does not imply any change in Japan’s territorial size. The GSI stated that these new findings “will not affect Japan’s territory and territorial waters.”

2. The Role of Geospatial Technology

According to Tokyo-based news agency Kyodo News, there are a few explanations for this surprising revelation. Firstly, advancements in geospatial technology have enhanced our ability to identify small clusters of islands that were historically misclassified as single landmasses.

3. Natural Landscape Changes

Moreover, natural disasters and extreme weather conditions are constantly reshaping the geography of the island nation, potentially leading to the gain or loss of land. For instance, according to Smithsonian Magazine, a Japanese islet known as Esanbe Hanakita Kojima, previously four-and-a-half feet above sea level, vanished due to erosion from wind and ice.

Conversely, Japan can also gain land, as in 2015 when a landslide resulted in a 984-foot strip of land attaching to Hokkaido, Japan’s second-largest island. Additionally, in 2021, an underwater volcanic eruption 750 miles south of Tokyo created a crescent-shaped island, as Kyodo News reported at the time. Islands that form due to volcanic activity often succumb to erosion, a fate seen with islands created and lost in 1904, 1914, and 1986.

4. Changing Definitions of Islands

Furthermore, the definition of what constitutes an island has evolved. The assessment from 1987 excluded sandbanks and islands located in lakes and rivers, as they were not recognized by the U.N. Convention on the Law of the Sea. Currently, the governing regulations define an island as a “naturally formed area of land, surrounded by water, which is above water at high tide.”

5. Japan’s Major Islands

Japan’s territory comprises four principal islands: Honshu (the main island home to cities like Tokyo, Kyoto, and Osaka); Hokkaido (Japan’s northernmost island featuring six national parks); Shikoku; and Kyushu. Additionally, smaller islands such as Naoshima — renowned as “art island” for its trio of modern and contemporary art museums — and Ōkunoshima, affectionately referred to as Usagi Jima or “rabbit island” due to the hundreds of wild rabbits inhabiting it, also play a significant role in Japan’s island landscape.