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Sagami Trough
The also Sagami Trench, Sagami Megathrust, or Sagami Subduction Zone is a long trough, which is the surface expression of the convergent plate boundary where the Philippine Sea Plate is being subducted under the Okhotsk Plate. It stretches from the Boso Triple Junction in the east, where it meets the Japan Trench, to Sagami Bay in the west, where it meets the Nankai Trough. It runs north of the Izu Islands chain and the Izu–Bonin–Mariana Arc (IBM). Megathrust earthquakes associated with the Sagami Trough, known as Kantō earthquakes, are a major threat to Tokyo and the Kantō Region because of the proximity to a population center (with over 36 million living in Tokyo's metro area, with a total of 43 million living in the Kanto Region) and the magnitude the Sagami Trough can create. Earthquakes The Sagami Trough megathrust generated the 1703 Genroku earthquake, which was the greatest rupture along the trough in the last thousand years, and the 1855 (Ansei) and 1923 (Gre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagami Trough Topographic
Sagami may refer to: *Sagami, an 11th-century ''waka'' poet *Sagami Province, an old province in Japan *Sagami River, a river in Kanagawa and Yamanashi *Sagami Bay, a bay south of Kanagawa Prefecture in Honshū * Sagami Line, a railway roughly along the east bank of the Sagami River *Sagami Railway, a railway company operating three lines in Kanagawa Prefecture, Japan **Sagami Railway Main Line, a railway line extending from Yokohama to Ebina **Sagami Railway Izumino Line Sagami may refer to: * Sagami, an 11th-century ''waka'' poet *Sagami Province, an old province in Japan *Sagami River, a river in Kanagawa and Yamanashi *Sagami Bay, a bay south of Kanagawa Prefecture in Honshū *Sagami Line, a railway roughly along ..., a railway line extending from Futamatagawa in Yokohama to Shōnandai in Fujisawa * Sagami-ji, a Buddhist temple in Hyōgo, Japan {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Izu Islands
The 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. 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. Geography The Izu islands stretch south-east from the Izu Peninsula on Honshu and cover an area of approximately . There are nine populated islands with a total population of 24,645 people () spread over . The largest of them is Izu Oshima (8,346 inhabitants, ), the smallest Toshima (292 inhabitants, .) 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 it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1923 Great Kantō Earthquake
The struck the Kantō Plain on the main Japanese island of Honshū at 11:58:44 JST (02:58:44 UTC) on Saturday, September 1, 1923. Varied accounts indicate the duration of the earthquake was between four and ten minutes. Extensive firestorms and even a fire whirl added to the death toll. Civil unrest after the disaster (i.e., the Kantō Massacre) has been documented. The earthquake had a magnitude of 7.9 on the moment magnitude scale (), with its focus deep beneath Izu Ōshima Island in Sagami Bay. The cause was a rupture of part of the convergent boundary where the Philippine Sea Plate is subducting beneath the Okhotsk Plate along the line of the Sagami Trough. Since 1960, September 1 has been designated by the Japanese government as , or a day in remembrance of and to prepare for major natural disasters including tsunami and typhoons. Drills, as well as knowledge promotion events, are centered around that date as well as awards ceremonies for people of merit. Earthquake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1855 Ansei Edo Earthquake
The , was the third Ansei Great Earthquake, which occurred during the late-Edo period. It occurred after the 1854 Nankai earthquake, which took place about a year prior. The earthquake occurred at 22:00 local time on 11 November. It had an epicenter close to Edo (now Tokyo), causing considerable damage in the Kantō region from the shaking and subsequent fires, with a death toll of 7,000–10,000 people and destroyed around 14,000 buildings. The earthquake had a magnitude of 7.0 on the surface wave magnitude scale and reached a maximum intensity of XI (''Extreme'') on the Mercalli intensity scale. The earthquake triggered a minor tsunami. Tectonic setting The Kanto area lies above a complex part of the convergent boundaries between the subducting Pacific and Philippine Sea Plates and the overriding Eurasian and North American Plates. Earthquakes with epicenters in the Kantō region may occur within the Eurasian Plate, at the Eurasian Plate/Philippine Sea Plate interface, within ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1703 Genroku Earthquake
The occurred at 02:00 local time on December 31 (17:00 December 30 UTC). The epicenter was near Edo, the forerunner of present-day Tokyo, in the southern part of the Kantō region, Japan. An estimated 2,300 people were killed by the shaking and subsequent fires. The earthquake triggered a major tsunami which caused many additional casualties, giving a total death toll of at least 5,233, possibly up to 10,000. Genroku is a Japanese era spanning from 1688 through 1704. Tectonic setting The Kantō Region lies at the complex triple junction, where the convergent boundaries between the subducting Pacific and Philippine Sea Plates and the overriding North American and Eurasian Plates meet. Earthquakes with epicenters in the Kanto region may occur within the Eurasian Plate, at the Eurasian Plate/Philippine Sea Plate interface, within the Philippine Sea Plate, at the Philippine Sea Plate/Pacific Plate interface or within the Pacific Plate. In addition to this set of major plates it h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megathrust
Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthquakes are the planet's most powerful, with moment magnitudes (''Mw'') that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes. The thrust faults responsible for megathrust earthquakes often lie at the bottom of oceanic trenches; in such cases, the earthquakes can abruptly displace the sea floor over a large area. As a result, megathrust earthquakes often generate tsunamis that are considerably more destructive than the earthquakes themselves. Teletsunamis can cross ocean basins to devastate areas far from the original earthquake. Terminology and mechanism The term ''megathrust'' refers to an extremely large thrust fault, typically formed at the plate interface along a subduction zone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kantō Region
The is a geographical area 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 Kanto Plain. The rest consists of the hills and mountains that form land borders with other regions of Japan. As the Kanto region contains Tokyo, the capital and largest city of Japan, the region is considered the center of Japan's politics and economy. According to the official census on October 1, 2010, by the Japan Statistics Bureau, the population was 42,607,376, amounting to approximately one third of the total population of Japan. Other definitions The Kantō regional governors' association (関東地方知事会, ''Kantō chihō chijikai'') assembles the prefectural governors of Ibaraki, Tochigi, Gunma, Saitama, Chiba, Tokyo, Kanagawa, Yamanashi, Nagano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kantō Earthquakes
A is a megathrust earthquake occurring in the Kantō region of Japan that originate from slippage in the Sagami Trough. Kantō earthquakes are thought to occur with a 200-year return period. Only two earthquakes in the Kantō region are thought to be megathrust earthquakes: * 1923 Great Kantō earthquake; most common usage * 1703 Genroku earthquake Other earthquakes in the Kantō region, which may or may not be due to slippage in the Sagami Trough: *The ''Ruijū Kokushi'' mentions an earthquake that struck the area in 818 * 1855 Edo earthquake See also * South Kantō earthquakes *List of earthquakes in Japan * Nankai megathrust earthquakes *Seismicity of the Sanriku coast The seismicity of the Sanriku coast identifies and describes the seismic activity of an area of Japan. Seismicity refers to the frequency, type and size of earthquakes experienced over a period of time. The is a descriptive term referring to th ... * Tōkai earthquakes {{DEFAULTSORT:Kanto Earthquake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megathrust Earthquakes
Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthquakes are the planet's most powerful, with moment magnitudes (''Mw'') that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes. The thrust faults responsible for megathrust earthquakes often lie at the bottom of oceanic trenches; in such cases, the earthquakes can abruptly displace the sea floor over a large area. As a result, megathrust earthquakes often generate tsunamis that are considerably more destructive than the earthquakes themselves. Teletsunamis can cross ocean basins to devastate areas far from the original earthquake. Terminology and mechanism The term ''megathrust'' refers to an extremely large thrust fault, typically formed at the plate interface along a subduction zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Izu–Bonin–Mariana Arc
The Izu–Bonin–Mariana (IBM) arc system is a tectonic plate convergent boundary in Micronesia. The IBM arc system extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, the Bonin Islands, and the Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea Plate in the Western Pacific Ocean. It is the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench. The IBM arc system formed as a result of subduction of the western Pacific plate. The IBM arc system now subducts mid- Jurassic to Early Cretaceous lithosphere, with younger lithosphere in the north and older lithosphere in the south, including the oldest (~170 million years old, or Ma) oceanic crust. Subduction rates vary from ~2 cm (1 inch) per year in the south to 6 cm (~2.5 inches) in the north. The volcanic islands that comprise these island ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nankai Trough
The is a submarine trough located south of the Nankaidō region of Japan's island of Honshu, extending approximately offshore. The underlying fault, the ''Nankai megathrust,'' is the source of the devastating Nankai megathrust earthquakes, while the trough itself is potentially a major source of hydrocarbon fuel, in the form of methane clathrate. In plate tectonics, the Nankai Trough marks a subduction zone that is caused by subduction of the Philippine Sea Plate beneath Japan, part of the Eurasian plate (Kanda et al., 2004). This plate boundary would be an oceanic trench except for a high flux of sediments that fills the trench. Within the Nankai Trough there is a large amount of deformed trench sediments (Ike, 2004), making one of Earth's best examples of accretionary prism. Furthermore, seismic reflection studies have revealed the presence of basement highs that are interpreted as seamounts that are covered in sediments (Ike, 2004). The northern part of the trough is known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megathrust
Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthquakes are the planet's most powerful, with moment magnitudes (''Mw'') that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes. The thrust faults responsible for megathrust earthquakes often lie at the bottom of oceanic trenches; in such cases, the earthquakes can abruptly displace the sea floor over a large area. As a result, megathrust earthquakes often generate tsunamis that are considerably more destructive than the earthquakes themselves. Teletsunamis can cross ocean basins to devastate areas far from the original earthquake. Terminology and mechanism The term ''megathrust'' refers to an extremely large thrust fault, typically formed at the plate interface along a subduction zone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
