There are now more than twice as many islands in Japan, government officials believe.
Sometimes, islands are created by natural forces, which is what happened after a volcano erupted in 2021. A new island was formed, located approximately 750 miles from Tokyo, according to Kyodo News.
That doesn’t happen all too often, however. Instead, the recent discovery of more than 7,000 islands isn’t due to seismic activity or other natural forces; it’s due to a recount performed using highly accurate digital maps and advanced surveying technology.
“The number of islands counted this time is significantly different from the 6,852 islands widely used as the number of islands in Japan,” according to the Geospatial Information Authority (GSI) of Japan, the agency behind the recount. “The islands of our country were counted under certain conditions. As a result, we have 14,125 islands.”
Importantly, GSI also notes that despite identifying 7,273 new islands, the discovery does not change the overall size of Japan.
“The results of this survey will not affect Japan’s territory and territorial waters,” GSI notes.
Why More Islands Are Counted
Japan’s previous count of 6,852 islands comes from a survey tabulated by hand by the Japanese Coast Guard in 1987. Several points now stand out about that counting.
First, the Coast Guard only counted islands with a circumference of 100 meters (328 feet) or greater that were shown on a map, Kyodo News explains.
Thanks to high-definition digital maps, scientists now know that groups of small islands were often misidentified as one larger island.
Also, islands in lakes and river sandbanks were not counted by the Coast Guard because in 1987, the U.N. Convention on the Law of the Sea didn’t allow classifying such landmasses as islands. Since then, however, the definition of an island has changed.
Today, “An island is a naturally formed area of land surrounded by water, which is above water at high tide,” according to the U.N. Convention on the Law of the Sea.
Finally, while the definition of an island may be defined by the U.N. Convention on the Law of the Sea, there is no international agreement regarding the “method of counting islands,” according to GSI.
“Therefore, when counting islands, in addition to islands based on laws and regulations, we counted land with a circumference of 0.1 kilometers [100 meters or 328 feet] or more that was judged to have been naturally formed among the land areas drawn on the map,” GSI explains.
Here’s how the count was completed.
First, GSI counted land masses in the new survey using its digitized map. It then cross-referenced that map with aerial photographs and other data to exclude artificially reclaimed land, Kyodo News reports.
While the computer detected more than 100,000 islands, only islands with a circumference of 100 meters or greater were added to the official count.
Why Japan’s Size Hasn’t Changed
The total size of Japan’s national territory is calculated using the same digital map regardless of the number of listed islands within the territory. In other words, GSI didn’t change the scope of the area that was surveyed again.
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