The Izu Islands ( 伊豆諸島 , Izu-shotō ) are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshū , Japan. Administratively, they form two towns and six villages; all part of Tokyo Prefecture . The largest is Izu Ōshima , usually called simply Ōshima.
23-587: Although usually called the " Seven Islands of Izu " ( 伊豆七島 in Japanese), there are in fact more than a dozen islands and islets. Nine among them are currently inhabited. The Izu islands stretch south-east from the Izu Peninsula on Honshu and cover an area of approximately 301.56 km (116.43 sq mi). There are nine populated islands with a total population of 24,645 people (as of 2009) spread over 296.56 km (114.50 sq mi). The largest of them
46-401: A radius of 3 nautical miles (about 5.4 kilometers) of Myōjin-shō. Shoyo conducted the survey of the sea area within a radius of about 10 nautical miles (about 18.5 kilometers) but farther than the area of the radius of 3 nautical miles (5.6 km). Manbou II works by the order of preprogrammed instructions and measures depth and water temperature. Bathymetric survey of Manbou II
69-429: Is Izu Oshima (8,346 inhabitants, 91.06 km (35.16 sq mi)), the smallest Toshima (292 inhabitants, 4.12 km (1.59 sq mi).) Of the inhabited islands, seven are traditionally referred to as the "Izu Seven": Oshima, Toshima, Niijima, Kozujima, Miyakejima, Hachijojima, and Mikurajima, though Shikinejima and Aogashima are sometimes included as well. Each of the islands has its unique character: Oshima
92-543: Is a submarine volcano located about 450 kilometers south of Tokyo on the Izu-Ogasawara Ridge in the Izu Islands . Volcanic activity has been detected there since 1869. Since then it has undergone more eruptions , the most powerful of which resulted in the appearance and disappearance of a small island . The name Myōjin-shō derives from a fishing boat, No.11 Myōjin-Maru of Yaizu City , Shizuoka Prefecture ,
115-435: Is almost a circle in the diameter of 7 by 9 kilometers and the height is 1,000 – 1,400meters. The diameter of the caldera floor is 5.6 kilometers and about 1,100 meters in depth. The central cone is a high formerly known as Takane-shō , 328 metres below sea level. Myōjin-shō is a post caldera cone formed in the northeastern part of the somma of the double volcano. It is a single conical cone and its height
138-562: Is noted for its active volcano Mt Mihara and camellias , Hachijo-kojima for its former penal colony, Mikurajima for dolphin watching, Niijima for its numerous beaches, Kozujima for its white sandy shores, Hachijojima for its well-preserved unique culture, and Miyakejima for the 2001 volcanic eruption. During the Edo period , Nii-jima, Miyake-jima, and Hachijō-jima served as places of exile for criminals. The subtropical Ogasawara Islands , which are also administratively part of Tokyo, lie further to
161-738: The Fuji-Hakone-Izu National Park . The four southernmost islands are not administered under any town or village in Hachijō Subprefecture, but are unincorporated areas . Torishima is now uninhabited but is an important bird refuge. Deserted islands between Aogashima and Ogasawara Islands, namely Bayonaise Rocks ( Beyonēzu Retsugan ), Smith Island ( Sumisu-tō ), Torishima , and Lot's Wife ( Sōfu-iwa ) do not belong to any municipality , because both Hachijō Town and Aogashima Village claim administrative rights. They are directly controlled by Hachijō Subprefecture instead. Though
184-618: The Hydrographic Department of the Maritime Safety Agency, was destroyed by the volcano, with the loss of its crew of 31 (including the nine scientists studying the eruption). Consequently, the Department developed Manbou (Sunfish), an unmanned radio operating survey boat, and has used it for the research of dangerous sea areas such as submarine volcanoes. This was the first time that volcanic activity had been detected using
207-516: The Meiji era . In addition, Hachijokojima, which became temporarily uninhabited during the 1965s, and Udoneshima and Torishima , where there are temporary residents, were once inhabited islands. And there are also other smaller uninhabited islands. As this name of the Seven Islands of Izu continued to be used even today, the islanders of the islands other than the Seven Islands feel discriminated., and
230-521: The SOFAR channel . In 1998 and 1999, the Hydrography Department conducted comprehensive sea bottom surveys around Myōjin-shō, using the state-of-the-art survey vessel Shoyo and Manbou II , the second generation Manbou . As a result of these surveys, a detailed picture of the seabed topography around Myōjin-shō was made for the first time. Manbou II conducted the survey of the sea area within
253-613: The Aogashima villagers in particular have petitioned not to use it at every opportunity. In connection with this, the affiliated organization of Tokyo, the "Izu Seven Islands Tourism Federation," was renamed to "Tokyo Islands Tourism Federation". However, this name is still used in sightseeing pamphlets at the travel agencies, such as those of Tokai Kisen that operate ferries to the various islands. 33°49′N 139°37′E / 33.817°N 139.617°E / 33.817; 139.617 My%C5%8Djin-sh%C5%8D Myōjin-shō ( 明神礁 )
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#1732844419556276-446: The Izu volcanic arc . The Izu arc ends there at a tectonic triple junction . Volcanic activity is frequent in the area. 31 people were killed when the research vessel Kaiyō Maru no 5 was destroyed during the 1953 eruption of Myōjin-shō . Volcanic activity, including the release of harmful gases, forced the evacuation of Miyake-jima in 2000. Residents were allowed to return permanently to
299-599: The Izu Archipelago are oceanic islands that formed relatively recently (within a few million years) without any previous connection to mainland Japan. In contrast to isolated Pacific islands, such as Hawaii and the Galápagos , the Izu Islands are located near the mainland and have thus been frequently colonized by various species by overseas dispersal from the mainland or from adjacent islands. This make them interesting for
322-578: The central cone of a double volcano with the Bayonnaise Rocks (rocks of 9.9 meters in height above the sea level) as a portion of the somma (Mita, 1949). As a result of the survey, however, the authors found that both Myōjin-shō and the Bayonnaise Rocks are cones on the somma of a double volcano. The foot of this double volcano lies 1,400 to 1,500 meters in depth and the size is about 30 by 25 kilometers east-west, north-south. The somma
345-462: The crew of which first witnessed the major volcanic eruption of 1952. The volcanic eruption from 1952 to 1953 was one of its biggest eruptions on record, with the repetitious appearance and disappearance of an island, which at one point reached over ten metres above sea level, before sinking after a major volcanic eruption in September 1953. On September 24, 1952, a survey vessel, Kaiyo Maru No. 5 of
368-496: The island in February 2005 but were required to carry gas masks in case of future volcanic emissions. To handle the various types of natural disasters threatening the region, including tsunamis, storm, floods, and volcanism, Tokyo metropolitan government has developed prevention and safety measures, including hazard maps and evacuation guidance, radios, signs, and a transport system for emergency supplies. A chain of volcanic islands,
391-412: The islands, by cargo-passengers boats , jetfoils , and aircraft , is supported by harbours on all inhabited islands and five airports (small islands can be reached by helicopter). There are 5 airports, 15 harbors, and 19 fishing ports. Flights from Tokyo take 30 minutes, while boats take 7–10 hours and jetfoils make the route in about two hours. Transportation on the islands is considered important to
414-456: The population on the Izu Islands has been dropping, the pace is less dramatic than on other isolated Japanese islands. The divergent Hachijō language is spoken on the islands. The primary industries are fisheries, agriculture, and tourism. The most scenic spots on the islands are crowded with tourists during summers. Popular tourist activities include swimming, scuba diving, surfing, fishing, bird watching and trekking. Transportation between
437-548: The quality of life, which is why about 215 km (134 mi) of paved main roads have been constructed to serve various kinds of vehicles. There was no electricity on the islands before 1953, but by 1962 98% of the area was receiving electricity. The islands occupy the northern portion of the Izu–Bonin–Mariana Arc which extends to the Izu Peninsula and Mount Fuji on the Honshū mainland which are northern extensions of
460-553: The seven inhabited islands of the Izu Islands that belong to the Tokyo Islands of Tokyo Prefecture , Japan . The name comes from the fact that there were the seven main inhabited islands in the Izu Islands during the Edo period : Izu Oshima , To-shima , Niijima , Kozushima , Miyakejima , Mikurajima , and Hachijojima . In fact, in addition to these seven islands, the Izu Islands have two other inhabited islands, Aogashima and Shikinejima , which have been inhabited since
483-417: The south. They form a far-flung archipelago of over thirty (30) islands some 1,000 km (621 mi) due south of Tokyo. The Izu Islands are divided into two towns (Oshima and Hachijojima) and six villages (the remaining inhabited islands.) Three subprefectures are formed above the municipalities as branch offices of the metropolitan government . All the islands (more than a dozen in total) lie within
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#1732844419556506-669: The studies of ecological and evolutionary processes. Campanula (Bellflower) colonized the entire archipelago in a single event. Similarly, the Euhadra snails, endemic to Japan, populated the islands in a single event and all individuals on inhabited islands possess an identical haplotype . The Apodemus mice, on the other hand, colonized the islands from the mainland in two independent events. 34°44′N 139°24′E / 34.733°N 139.400°E / 34.733; 139.400 Seven Islands of Izu The Seven Islands of Izu ( Japanese : 伊豆七島 = Izu Shichitō) are
529-407: Was carried out by using the "PRD-601" echo sounder at intervals of 0.2 nautical miles (about 370 meters). Shoyo conducted a comprehensive survey including the geological and geophysical surveys of sea bottom. Bathymetric survey of Shoyo was carried out by using a "Seabeam 2112" echo sounder at intervals of 0.5 nautical miles (about 930 meters). Previously, Myōjin-shō was considered to be
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