Hakata Bay - Geography

Geography

The Bay is defined by Shoal Umi-no-nakamichi and Tombolo Shika-no-shima (Shika Island) to the north, and Genkai-jima (Genkai Island) to the northwest, and the Itoshima Peninsula to the west. Five wards of Fukuoka city border on the bay, which is sometimes labeled "Fukuoka Bay" on maps. Sometimes, the bay is divided into Hakata, Fukuoka, and Imazu Bays, though for simplicity's sake, the term "Hakata Bay" is commonly used as a catch-all to refer to all three.

The bay is roughly 10 km from north to south, and 20 km from east to west, covering an area of roughly 133 km². The coastline stretches 128 km. The mouth of the bay is only 7.7 km wide, shielding it to a great extent from the waves of the Strait. The bay is only 10 metres deep on average, 23 m at its deepest point, though the tides bring a two metre change in the water level. Set routes are used, therefore, through the bay, to protect ships' drafts.

Land reclamation began to be undertaken before the Meiji period, and continued into the post-war period. Since 1945, 1167 square kilometres of land have been reclaimed from the bay, primarily to improve or reinforce the effective functioning of the port. In 1994, an artificial island was begun to created and called "Island City" (アイランドシティ, Airandoshiti).

Some particular petrified trees in the area are said to have been the masts of ships used in Empress Jingū's third century invasion of Korea. Veins of mica and pegmatite under the bay, part of a geologic fault, are under governmental protection.

Much of the area is included in the Genkai National Park, and efforts are made to maintain and preserve the natural features and environment both in the bay and on its islands. Though much of the shoreline is natural, some parts, particularly in and around the port itself, are artificial and developed upon; the bay's shoreline was officially designated as natural wilderness and parkland somewhat crudely.