is a bay located in the southern

Kantō region The is a geography, geographical region of Honshu, the largest island of Japan. In a common definition, the region includes the Greater Tokyo Area and encompasses seven prefectures of Japan, prefectures: Chiba Prefecture, Chiba, Gunma Prefe ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

spanning the coasts of

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

Kanagawa Prefecture is a Prefectures of Japan, prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the List of Japanese prefectures by population, second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-dens ...

, and

Chiba Prefecture is a Prefectures of Japan, prefecture of Japan located in the Kantō region of Honshu. Chiba Prefecture has a population of 6,278,060 (1 June 2019) and has a geographic area of . Chiba Prefecture borders Ibaraki Prefecture to the north, Saitama ...

, on the southern coast of the island of

Honshu , historically known as , is the largest of the four main islands of Japan. It lies between the Pacific Ocean (east) and the Sea of Japan (west). It is the list of islands by area, seventh-largest island in the world, and the list of islands by ...

. Tokyo Bay is connected to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

by the Uraga Channel. The Tokyo Bay region is the most populous and the largest industrialized area in Japan.

Names

In ancient times, the Japanese knew Tokyo Bay as the . By the Azuchi–Momoyama period (1568–1600) the area had become known as after the city of Edo. The bay took its present name in modern times, after the Imperial court moved to Edo and renamed the city Tokyo in 1868.

Geography

Tokyo Bay juts prominently into the

Kantō Plain The , in the Kantō region of central Honshu, is the largest plain in Japan. Its 17,000 km2 covers more than half of the region extending over Tokyo, Saitama Prefecture, Kanagawa Prefecture, Chiba Prefecture, Gunma Prefecture, Tochigi Prefe ...

. It is surrounded by the Bōsō Peninsula in

to the east and the Miura Peninsula in

to the west. The shore of Tokyo Bay consists of a diluvial

plateau In geology and physical geography, a plateau (; ; : plateaus or plateaux), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. ...

and is subject to rapid marine

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

. Sediments on the shore of the bay make for a smooth, continuous shoreline.

Boundaries

In a narrow sense, Tokyo Bay is the area north of the straight line from Cape Kannon on the west of Miura Peninsula to Cape Futtsu on the east Bōsō Peninsula. This area covers about in 2012, reclamation projects continue to slowly shrink the bay. In a broader sense, Tokyo Bay includes the Uraga Channel. By this definition the bay opens from an area north of the straight line from Cape Tsurugisaki on the east of Miura Peninsula to Cape Sunosaki on the west of the Boso Peninsula. This area covers about . The area of Tokyo Bay combined with the Uraga Channel covers .

Depth

The shoal between Cape Futtsu in Chiba Prefecture and Cape Honmaku in

Yokohama is the List of cities in Japan, second-largest city in Japan by population as well as by area, and the country's most populous Municipalities of Japan, municipality. It is the capital and most populous city in Kanagawa Prefecture, with a popu ...

is known as Nakanose, and has a depth of . North of this area the bay has a depth of and an uncomplicated underwater

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

. Areas south of Nakanose are significantly deeper moving towards the Pacific Ocean.

Islands

The only natural island in Tokyo Bay is Sarushima () at Yokosuka, Kanagawa Prefecture. Sarushima was one of the locations fortified with coastal artillery during the Bakumatsu period and was subsequently incorporated into the Tokyo Bay Fortress during the

Meiji period The was an era of Japanese history that extended from October 23, 1868, to July 30, 1912. The Meiji era was the first half of the Empire of Japan, when the Japanese people moved from being an isolated feudal society at risk of colonizatio ...

. The Imperial Japanese Navy maintained a degaussing station on the island until the end of World War II. The island is now uninhabited and is a marine park. Many artificial islands were built as naval fortifications in the Meiji and Taishō periods. After World War II these islands were converted to residential or recreational use. Odaiba, also known as ''Daiba'', was one of six artificial islands constructed in 1853 as a fortification to protect the

Tokugawa shogunate The Tokugawa shogunate, also known as the was the military government of Japan during the Edo period from 1603 to 1868. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil wars ...

at Edo, and was known as the Shinagawa Daiba. After World War II Odaiba was incorporated into Tokyo and redeveloped for commercial and recreational use. Before World War II,

Yumenoshima is a district in Kōtō, Tokyo, Japan, consisting of an artificial island Land reclamation, built using waste landfill in Tokyo Bay. It is not the first such island in the bay (see Umi-no-mori :ja:海の森公園). At current fill rates, there w ...

was planned as an airfield (one of the largest in the world at the time), but after the US military expansion of Haneda Airport following World War II, the plan of the airfield fell through. The island briefly opened as a public beach before being repurposed and used as a

landfill A landfill is a site for the disposal of waste materials. It is the oldest and most common form of waste disposal, although the systematic burial of waste with daily, intermediate and final covers only began in the 1940s. In the past, waste was ...

between 1957 and 1967 to dispose of the large quantities of garbage from the Tokyo Metropolitan Area. The reclaimed land now hosts

Yumenoshima Park is a sports park in Yumenoshima, Kōtō, Kōtō Ward, Tokyo, Japan. It was made by improving a landfill site called Yumenoshima, which was the final disposal site for garbage from 1957 until 1967. Yumenoshima was the site of the Archery at the 2 ...

with numerous recreational facilities. Hakkei Island (), formerly Landfill Number 14, was constructed in 1985 and is home to Yokohama Hakkeijima Sea Paradise. Other artificial islands include Heiwa, Katsushima, Shōwa, Keihin, and Higashiōgi islands.

Rivers

Numerous rivers empty into Tokyo Bay, and all provide water for residential and industrial areas along the bay. The Tama and Sumida rivers empty into the bay at Tokyo. The Edo River empties into Tokyo Bay between Tokyo and Chiba Prefecture. The Obitsu and Yōrō rivers empty into the bay in Chiba Prefecture.

Land reclamation

Land reclamation has been carried out along the coast of Tokyo Bay since the Meiji period. Areas along the shore with a depth of less than are simplest to carry out

, and

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

from the floor of Tokyo Bay is used for these projects. The topography of the shoreline of Tokyo Bay differs greatly from that of the pre-modern period due to ongoing land reclamation projects. Tokyo Bay includes about of reclaimed land area in 2012. Aggregate household waste production is enormous in Greater Tokyo, there is little room for traditional garbage disposal sites; waste is rigorously sorted at the household, much of it is turned into ash and further recycled into bay landfill.

Bridges

The Tokyo Bay Aqua-Line bridge-tunnel crosses Tokyo Bay between Kawasaki and Kisarazu; Tokyo-Wan Ferry also crosses the bay toward the Uraga Channel between Kurihama (in Yokosuka) and Kanaya (in Futtsu on the Chiba side).

Development

Fishing

Tokyo Bay was a historical center of the

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, ...

industry, a source of shellfish, and other aquaculture. These industries decreased with the industrialization of the Tokyo Bay region early in the 20th century, and almost completely ceased with the construction of the Keihin and Keiyō industrial zones directly after

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

Ports

A number of Japan's most important

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...

s are located in Tokyo Bay. The Port of Yokohama, the Port of Chiba, the Port of Tokyo, the Port of Kawasaki, the Port of Yokosuka, the Port of Kisarazu, rank not only as the busiest ports in Japan, but also in the Asia-Pacific Region.

Industrial zones

Industrial zones on Tokyo Bay were developed as early as the

Meiji era The was an Japanese era name, era of History of Japan, Japanese history that extended from October 23, 1868, to July 30, 1912. The Meiji era was the first half of the Empire of Japan, when the Japanese people moved from being an isolated feu ...

(1868–1912). The Keihin Industrial Zone was built on reclaimed land in Kanagawa Prefecture to the west of Tokyo. This was expanded to the Keiyō Industrial Zone in Chiba Prefecture along the north and east coasts of Tokyo Bay after

. The development of the two zones has resulted in the largest industrialized area in Japan. The large-scale industrial zones of the coastal Tokyo region have caused significant air and

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

pollution.

Military facilities

The Port of Yokosuka contains the naval bases of the Japan Maritime Self-Defense Force and the United States Forces Japan.

History

Perry Expedition

Tokyo Bay was the venue for the Perry Expedition, which involved two separate trips from 1853 to 1854 between the United States and Japan by Commodore Matthew Perry (1794–1858). Perry sailed on his four " Black Ships" into Edo Bay on July 8, 1853, and began negotiations with the

that led to a peace and trade

treaty A treaty is a formal, legally binding written agreement between sovereign states and/or international organizations that is governed by international law. A treaty may also be known as an international agreement, protocol, covenant, convention ...

between the United States and Japan in 1854.

World War II

The Japanese Instrument of Surrender at the end of

was signed on September 2, 1945, on board , which was anchored at 35° 21′ 17″ N 139° 45′ 36″ E. A flag from one of Commodore Perry's ships was flown in from the Naval Academy Museum and displayed at the ceremony.

References

{{Authority control Bays of Japan Landforms of Tokyo Geography of Yokohama Landforms of Chiba Prefecture Landforms of Kanagawa Prefecture