Japan, Sea

Japan, Sea of

 or East Sea

Branch of the western Pacific Ocean, bounded by Japan, by Sakhalin Island, and by Russia and Korea on the Asian mainland. It has a surface area of about 377,600 sq mi (978,000 sq km), a mean depth of 5,748 ft (1,752 m), and a maximum depth of 12,276 ft (3,742 m). Its relatively warm waters contribute greatly to the mild climate of Japan. The growing trade among East Asian countries has increased its use as a commercial waterway.