East China Sea

The East China Sea is a marginal sea east of China. It is a part of the Pacific Ocean and covers an area of roughly 1249000 km².

Geography
The East China Sea is bounded on the east by Kyūshū and the Ryukyu Islands of Japan, on the south by the island of Taiwan, and on the west by mainland China and the Asian continent. It is connected with the South China Sea by the Taiwan Strait and with the Sea of Japan by the Korea Strait; it opens in the north to the Yellow Sea.

States with borders on the sea (clockwise from north) include: South Korea, Japan, Republic of China (Taiwan) and the People's Republic of China.

Extent
The International Hydrographic Organization defines the limits of the "Eastern China Sea (Tung Hai)" as follows:


 * On the South.
 * The Northern limit of the South China Sea [From Fuki Kaku the North point of Formosa to Kiushan Tao (Turnabout Island) on to the South point of Haitan Tao (25°25' N) and thence Westward on the parallel of 25°24' North to the coast of Fukien ], thence from Santyo the Northeastern point of Formosa to the West point of Yonakuni Island and thence to Haderuma Sima (24°03′ N, 123°47′ E).
 * On the East.
 * From Haderuma Sima a line including the Miyako Retto to the East point of Miyako Sima and thence to Okinan Kaku, the Southern extremity of Okinawa Sima through this island to Ada-Ko Sima (Sidmouth Island) on to the East point of Kikai Sima (28°20' N) through Tanegra Sima (30°30' N) to the North point thereof and on to Hi-Saki (31°17' N) in Kyusyu.
 * On the North.
 * From Nomo Saki (32°35' N) in Kyusyu to the South point of Hukae Sima (Goto Retto) and on through this island to Ose Saki (Cape Goto) and to Hunan Kan, the South point of Saisyu To (Quelpart), through this island to its Western extreme and thence along the parallel of 33°17' North to the mainland.
 * On the West.
 * The mainland of China.

Rivers
The Yangtze River (Chang Jiang) is the largest river flowing into the East China Sea.

Islands and reefs

 * Senkaku Islands (Japanese) or Diaoyu Islands (Chinese). Disputed.
 * Tong Island

There is a cluster of submerged reefs in the northern East China Sea. These include:


 * Socotra Rock, also called Suyan Rock or Ieodo, subject of an EEZ dispute between the People's Republic of China and South Korea.
 * Hupijiao Rock (虎皮礁)
 * Yajiao Rock (鸭礁)

Nomenclature
During the 19th century, the sea was known as the Mer de Corée (Sea of Korea) in French. It was one of the three main seas within East Asia, the other two being Mer du Japon (Sea of Japan) to the north and Mer de Chine (Sea of China, today the South China Sea) to the south.

Until World War II, the sea was referred to as 東支那海 (Higashi Shina Kai; "East Shina Sea") in Japanese. In 2004, official documents of the Japanese Foreign Ministry and other departments switched to the name 東シナ海 (pronounced the same), which has become the standard usage in Japan.

EEZ disputes
There are disputes between the People's Republic of China (PRC), Japan, and South Korea over the extent of their respective exclusive economic zones.

The dispute between the PRC and Japan concerns the different application of the 1982 UNCLOS, which both nations have ratified. China proposed the application of UNCLOS, considering the natural prolongation of its continental shelf, advocating that the EEZ extends as far as the Okinawa Trough. Its Ministry of Foreign Affairs has stated that "the natural prolongation of the continental shelf of China in the East China Sea extends to the Okinawa Trough and beyond 200 nautical miles from the baselines from which the breadth of the territorial sea of China is measured," which is applicable to the relevant UNCLOS provisions that support China's right to the natural shelf. In 2012, China presented a submission under the UNCLOS concerning the outer limits of the continental shelf to the UN. Japan, based on UNCLOS, proposed the Median line division of the EEZ.

Under the United Nations' Law of the Sea, the PRC claims the disputed ocean territory as its own Exclusive Economic Zone (EEZ) due to its being part of PRC's natural extension of its continental shelf, while Japan claims the disputed ocean territory as its own EEZ because it is within 200 nautical miles (370 km) from Japan's coast, and proposed a median line as the boundary between the EEZ of China and Japan. About 40,000 square kilometers of EEZ are in dispute. China and Japan both claim 200 nautical miles EEZ rights, but the East China Sea width is only 360 nautical miles. China claims an EEZ extending to the eastern end of the Chinese continental shelf (based on UNCLOS III) which goes deep into the Japanese's claimed EEZ.

In 1995, the People's Republic of China (PRC) discovered an undersea natural gas field in the East China Sea, namely the Chunxiao gas field, which lies within the Chinese EEZ while Japan believes it is connected to other possible reserves beyond the median line. Japan has objected to PRC development of natural gas resources in the East China Sea near an area where the two countries Exclusive Economic Zone (EEZ) claims overlap. The specific development in dispute is the PRC's drilling in the Chunxiao gas field, which is located in undisputed areas on China's side, three or four miles (6 km) west of the median line proposed by Japan. Japan maintains that although the Chunxiao gas field rigs are on the PRC side of a median line that Tokyo regards as the two sides' sea boundary, they may tap into a field that stretches underground into the disputed area. Japan therefore seeks a share in the natural gas resources. The gas fields in the Xihu Sag area in the East China Sea (Canxue, Baoyunting, Chunxiao, Duanqiao, Wuyunting, and Tianwaitian) are estimated to hold proven reserves of 364 BCF of natural gas. Commercial operations began 2006. In June 2008, both sides agreed to jointly develop the Chunxiao gas fields.

Rounds of disputes about island ownership in the East China Sea have triggered both official and civilian protests between China and Japan. The dispute between PRC and South Korea concerns Socotra Rock, a submerged reef on which South Korea has constructed a scientific research station. While neither country claims the rock as territory, the PRC has objected to Korean activities there as a breach of its EEZ rights.

East China Sea in astronomy
Possibly, East China Sea (Donghai in Chinese) is represented with the star Eta Serpentis in asterism Left Wall, Heavenly Market enclosure (see Chinese constellation).