|Native name||東京湾 (Tōkyō-wan)|
|River sources|| Ara River |
|Ocean/sea sources||Pacific Ocean|
|Surface area||1,500 km2 (580 sq mi)|
|Average depth||40 m (130 ft)|
|Max. depth||70 m (230 ft)|
Tokyo Bay (東京湾, Tōkyō-wan) is a bay located in the southern Kantō region of Japan, and spans the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. The Tokyo Bay region is the most populous and the largest industrialized area in Japan.
In ancient times, Japanese knew Tokyo Bay as the uchi-umi (内海) , which means "inner sea". By the Azuchi–Momoyama period (1568–1600) the area had become known as Edo Bay (江戸湾, Edo-wan) 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.
Tokyo Bay juts prominently into the Kantō Plain.It is surrounded by the Bōsō Peninsula in Chiba Prefecture to the east and the Miura Peninsula in Kanagawa Prefecture to the west. The shore of Tokyo Bay consists of a diluvial plateau and is subject to rapid marine erosion. Sediments on the shore of the bay make for a smooth, continuous shoreline.
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 922 km2 (356 sq mi) 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 1,100 km2 (420 sq mi). The area of Tokyo Bay combined with the Uraga Channel covers 1,500 km2 (580 sq mi).
The shoal between Cape Futtsu in Chiba Prefecture and Cape Honmaku in Yokohama is known as Nakanose, and has a depth of 20 m (66 ft). North of this area the bay has a depth of 40 m (130 ft) and an uncomplicated underwater topography. Areas south of Nakanose are significantly deeper moving towards the Pacific Ocean.
The only natural island in Tokyo Bay is Sarushima (0.055 km2 (0.021 sq mi)) 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 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 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. 0.24 km2 (0.093 sq mi)), 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.Before World War II, Yumenoshima 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 between 1957 and 1967 to dispose of the large quantities of garbage from the Tokyo Metropolitan Area. The reclaimed land now hosts Yumenoshima Park with numerous recreational facilities. Hakkei Island (
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 has been carried out along the coast of Tokyo Bay since the Meiji period. Areas along the shore with a depth of less than 5 m (16 ft) are simplest to carry out landfill, and sand 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 249 km2 (96 sq mi) 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.
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).
Tokyo Bay was a historical center of the fishing 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.
A number of Japan's most important ports 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 on Tokyo Bay were developed as early as the Meiji era (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 World War II. 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 pollution.
The Port of Yokosuka contains the naval bases of the Japan Maritime Self-Defense Force and the United States Forces Japan.
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 Tokugawa shogunate that led to a peace and trade treaty between the United States and Japan in 1854.
The Japanese Instrument of Surrender at the end of World War II was signed on September 2, 1945, on board USS Missouri (BB-63), 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.
Chiba Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Chiba Prefecture has a population of 6,278,060 and has a geographic area of 5,157 km2 (1,991 sq mi). Chiba Prefecture borders Ibaraki Prefecture to the north, Saitama Prefecture to the northwest, and Tokyo to the west.
The Kantō region is a geographical region of Honshu, the largest island of Japan. In a common definition, the region includes the Greater Tokyo Area and encompasses seven prefectures: Gunma, Tochigi, Ibaraki, Saitama, Tokyo, Chiba, and Kanagawa. Slightly more than 45 percent of the land area within its boundaries is the Kantō Plain. The rest consists of the hills and mountains that form land borders with other regions of Japan.
Narashino is a city located in Chiba Prefecture, Japan. As of 30 November 2020, the city had an estimated population of 175,292 in 81,985 households and a population density of 8400 persons per km². The total area of the city is 20.97 square kilometres (8.10 sq mi)
Kamogawa is a city located in Chiba Prefecture, Japan. As of 1 December 2020, the city had an estimated population of 31,722 in 14,558 households and a population density of 170 persons per km². The total area of the city is 191.14 square kilometres (73.80 sq mi).
Futtsu is a city located in Chiba Prefecture, Japan. As of 1 November 2020, the city had an estimated population of 42,476 in 18,115 households and a population density of 210 persons per km². The total area of the city is 205.53 square kilometres (79.36 sq mi).
The Uraga Channel is a waterway connecting Tokyo Bay to the Sagami Gulf. It is an important channel for ships headed from Tokyo, Yokohama, and Chiba to the Pacific Ocean and beyond.
The Bōsō Peninsula is a peninsula that encompasses the entirety of Chiba Prefecture on Honshu, the largest island of Japan. It is part of the Greater Tokyo Area. It forms the eastern edge of Tokyo Bay, separating it from the Pacific Ocean. The peninsula covers approximately 5,034 square kilometres (1,944 sq mi).
Isumi is a city located in Chiba Prefecture, Japan. As of 1 November 2020, the city had an estimated population of 37,206 in 17,004 households and a population density of 240 persons per km². The total area of the city is 157.44 square kilometres (60.79 sq mi).
Kyonan is a town located in Chiba Prefecture, Japan. As of 1 November 2020, the town had an estimated population of 7,409 in 3543 households and a population density of 160 persons per km². The total area of the city is 45.16 square kilometres (17.44 sq mi).
Kujūkuri Beach is a sandy beach that occupies much of the northeast coast of the Bōsō Peninsula in Chiba Prefecture, Japan. The beach is approximately 60 kilometres (37 mi) long, making it the second longest beach in Japan. Kujūkuri Beach is a popular swimming and surfing destination for inhabitants of Greater Tokyo. The beach is protected as part of Kujūkuri Prefectural Natural Park.
Ōtsu is the capital city of Shiga Prefecture, Japan. As of 1 October 2021, the city had an estimated population of 343,991 in 153,458 households and a population density of 740 persons per km2. The total area of the city is 464.51 square kilometres (179.35 sq mi).
The Edo River is a river in the Kantō region of Japan. It splits from the Tone River at the northernmost tip of Noda City in the Sekiyado district, crosses through Nagareyama and Matsudo, and empties into Tokyo Bay at Ichikawa, Chiba Prefecture. The Edo forms the borders between Tokyo, Chiba, and Saitama prefectures. The Edo River is 59.5 kilometres (37.0 mi) long.
Inage Ward is one of the six wards of the city of Chiba in Chiba Prefecture, Japan. As of April 2012, the ward had an estimated population of 156,860 and a population density of 7,380 persons per km2. The total area was 21.25 square kilometres (8.20 sq mi).
Mount Nokogiri literally "saw mountain" is a low mountain on the Bōsō Peninsula on Honshu, Japan. It lies on the southern border of the city of Futtsu and the town Kyonan in Awa District in Chiba Prefecture.
Cape Myōgane is a cape located on the border of Futtsu and Kyonan, Chiba, Japan, where Mount Nokogiri on its western end precipitously falls into the Uraga Channel to Tokyo Bay.
The Port of Chiba is the largest seaport in Japan, located in Chiba Prefecture on the interior of Tokyo Bay. The Port spans 24,800 hectares across the cities of Ichikawa, Funabashi, Narashino, Chiba, Ichihara, and Sodegaura.
Cape Suno is a cape on the Pacific Ocean, in the city of Tateyama, Chiba Prefecture, Japan. The cape is located at the southwestern point of Bōsō Peninsula on the island of Honshu, and marks the point between the inner and outer parts of the peninsula.
The Shimōsa Plateau is a plateau on the Kantō Plain in central Honshu, Japan. The plateau covers most of northern Chiba Prefecture. The plateau was historically richly agricultural, but in the 20th century the western and central Shimōsa Plateau became one of the major industrial areas of Japan, as well as a large-scale bedroom community of the Tokyo Metropolitan Region. Narita International Airport is located in the center of the Shimōsa Plateau.
Tokyo Bay Fortress was the name of a group of coastal fortifications built to guard the entrance to Tokyo Bay and thus the city of Tokyo from attack from the sea. These gun batteries and fortifications ceased to be used after the end of World War II.