Tokyo Bay 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. Its old name was Edo
Bay. The Tokyo Bay region is both the most populous and largest industrialized
area in Japan. Naming
In ancient times, Japanese knew Tokyo Bay as the uchi-umi or "inner sea". By
the Azuchi-Momoyama period the area had become known as Edo Bay, a reference to
the city of Edo. The bay took its present name of Tokyo Bay in modern
times, after the Imperial court moved to Edo and renamed that city as Tokyo in
1868. Geography
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.
= 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 922 square
kilometres. 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
square kilometres. The area of Tokyo Bay combined with the Uraga Channel covers
1,500 square kilometres. = Depth =
The shoal between Cape Futtsu in Chiba Prefecture and Cape Honmaku in Yokohama
is known as Nakanose, and has a depth of 20 metres. North of this area the bay
has a depth of 40 metres and an uncomplicated submarine topography.
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 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 period. 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.
After World War II Yumenoshima was planned as a solution to dispose of the
large quantities of garbage from the Tokyo Metropolitan Area. The island was
constructed between 1957 and 1967 hosts 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 5 metres 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 square kilometres of reclaimed land area.
= 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 and Kanaya.
Development = Fishing =
Tokyo Bay was historically a rich 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.
= Ports = 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 = Industrial zones on Tokyo Bay were
developed as early as the Meiji Era. The Keihin Industrial Zone was built on
reclaimed land in Kanagawa Prefecture to the west of Tokyo. This was expanded to
the Keiyo 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. = 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. 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.
= World War II = The Japanese Instrument of Surrender at
the end of World War II was signed on 2 September 1945 on board USS Missouri,
which was anchored at 35° 21′ 17″ N 139° 45′ 36″ E. During the ceremony, a flag
from one of Perry's ships was flown. See also
Port of Tokyo Uraga Channel
Miura Peninsula Bōsō Peninsula
Keihin Keiyō
References