Japan on Saturday extended its designation of its continental shelf to the eastern part of islands some 1,000 kilometers south of Tokyo, enabling the resource-poor country to start research on extracting maritime natural resources such as rare metals from the region. A revised Cabinet order took effect designating a significant portion of the Ogasawara Plateau sea area as part of its continental shelf, an area of around 120,000 square kilometers. Its move to enlarge the shelf has triggered opposition from China. “The expanded continental shelf represents around half of the area of Japan’s Hons…