The Sea of Japan is a marginal sea of the western Pacific Ocean, bordered by Japan, Korea, North Korea and Russia and is referred to in North Korea as the Korea East Sea and in South Korea as the East Sea. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure.
It is connected to other seas by five shallow straits: the Strait of Tartary between the Asian mainland and Sakhalin; La Perouse Strait between the islands of Sakhalin and Hokkaidō; the Tsugaru Strait between the islands of Hokkaidō and Honshū; the Kanmon Straits between the islands of Honshū and Kyūshū; and the Korea Strait (genkainada) between the Korean Peninsula and the island of Kyūshū. The Korea Strait is composed of the Western Channel and the Tsushima Strait, on either side of Tsushima Island.
The sea has three major basins: the Yamato Basin in the southeast; the Japan Basin in the north; and the Tsushima Basin (Ulleung Basin) in the southwest. The Japan Basin has the deepest areas of the sea, while the Tsushima Basin has the shallowest.
On the eastern shores, the continental shelves of the sea are wide, but on the western shores, particularly along the Korean coast, they are narrow, averaging about 30 kilometres wide.
The Tsushima Warm Current, a branch of Kuroshio Current, flows northward through the Korea Strait along the Japanese shore, and the Liman Cold Current flows southward through the Strait of Tartary along the Russian shore.
There is no controversy regarding the fact that the rise of "Sea of Japan" as the dominant appellation is relatively recent :
- the Japanese claim that it was commonly adopted during the early 19th century
- the Koreans claim that the change was imposed during the Japanese Occupation (early 20th century - with an official validation in 1929), and that unlike most other names changes forced during that period, it was never reverted afterwards
Both South Korea and North Korea have advocated for the end of what they consider a colonial heritage :
- South Korea wants the "East Sea" name to be restored, and claims that the "Sea of Japan" appellation is not anterior to the "Sea of Korea/Korean Sea" appellation
- North Korea wants the "East Sea of Korea" name to be restored
As a result of Korean objections to the name "Sea of Japan", some English-language publications refer to it as "Sea of Japan (East Sea)", incorporating a version of the Korean name.
On August 27, 2007, both Korean states made separate proposals to the Ninth Conference on the Standardization of Geographical Names instituted by the United Nations. The conference made no decision on the issue but called on all parties to find a commonly accepted solution. The chairman of the session stated that "individual countries could not impose specific names on the international community and standardization could only be promoted when a consensus existed".