is a group of
volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates a ...
rocks in the
Philippine Sea about south of
Tokyo
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and List of cities in Japan, largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, ...
and south-southeast of
Aogashima
is a volcanic island to the south of Japan in northernmost Micronesia. It is the southernmost and most isolated inhabited island of the Izus, which are politically and administratively part of Japan but geographically not part of the Japanes ...
, in the south portion of the
Izu archipelago,
Japan. The rocks were discovered by the French
corvette ''Bayonnaise'' in 1850, while surveying the islands south of
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. The Tokyo Bay region is both the most populous ...
.
Geography
The rocks are the exposed portion of the western ridge of a submarine
volcanic caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
, approximately in diameter at a depth of approximately .
[Christopher G. Newhall, Daniel Dzurisin: ''Historical Unrest at large Calderas of the World.'' Volume 1, U.S. Geological Survey Bulletin 1855, Washington 1988, p. 506]
Bathymetric map around "Bayonnaise Rocks" based on Basic Map of the Sea
(1:50.000, retrieved 2012-12-13). The above sea-level portion has a surface area of approximately 0.01 square kilometers, with a summit height of . and consists of three large rocks and many smaller rocks.
The caldera is known to have erupted in 1869–1871, 1896, 1906, 1915, 1934, 1946, 1952–1955, 1957–1960, and 1970. The last known
submarine eruption
Submarine eruptions are those volcano eruptions which take place beneath the surface of water. These occur at constructive margins, subduction zones and within tectonic plates due to hotspots. This eruption style is far more prevalent than subae ...
of the caldera was in 1988, which discolored the local water.
On the northeast rim of the same caldera to the east of the Bayonnaise Rocks is a submerged reef named , which is a post-caldera cone with a depth of approximately . During a submarine volcanic eruption of 17 September 1952, an ephemeral island was formed, with a height of , which was created and destroyed several times by volcanic activity until completely disappearing on 23 September 1953. The following day, an eruption killed 31 researchers and crewmen aboard the Maritime Safety Agency survey ship No.5 Kaiyo-Maru. The island reappeared on 11 October, sinking again on 11 March 1954 and reappeared one more time between 5 April and 3 September 1954.
Vegetation is sparse among the Bayonnaise Rocks. The islands are a resting place for
migratory bird
Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting b ...
s. Located in the
Kuroshio Current
The , also known as the Black or or the is a north-flowing, warm ocean current on the west side of the North Pacific Ocean basin. It was named for the deep blue appearance of its waters. Similar to the Gulf Stream in the North Atlantic, the Ku ...
, the area has abundant sea life, and is popular with sports fishermen.
See also
*
Izu Islands
*
Desert island
A desert island, deserted island, or uninhabited island, is an island, islet or atoll that is not permanently populated by humans. Uninhabited islands are often depicted in films or stories about shipwrecked people, and are also used as stereot ...
*
List of islands
This is a list of the lists of islands in the world grouped by country, by continent, by body of water
A body of water or waterbody (often spelled water body) is any significant accumulation of water on the surface of Earth or another plan ...
*
List of islands in Japan
Japan is an archipelago of 6,852 islands, of which approximately 260 are inhabited. Japan is the largest island country in East Asia and the fourth largest in the world.
Main islands
The four ''main islands'' of Japan are:Imperial Japanese ...
References
External links
* - Japan Meteorological Agency
*
Bayonnaise Rocks Volcano- volcanolive.com
{{Authority control
Izu Islands
Uninhabited islands of Japan
Volcanoes of Japan
Islands of Tokyo