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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 Earthquake
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 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (Grea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Return Period
A return period, also known as a recurrence interval or repeat interval, is an average time or an estimated average time between events such as earthquakes, floods, landslides, or river discharge flows to occur. It is a statistical measurement typically based on historic data over an extended period, and is used usually for risk analysis. Examples include deciding whether a project should be allowed to go forward in a zone of a certain risk or designing structures to withstand events with a certain return period. The following analysis assumes that the probability of the event occurring does not vary over time and is independent of past events. Estimating a return period Recurrence interval = :''n'' number of years on record; :''m'' is the rank of observed occurrences when arranged in descending order For floods, the event may be measured in terms of m3/s or height; for storm surges, in terms of the height of the surge, and similarly for other events.This is the Weibull's For ... [...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 T ... [...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 has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruijū Kokushi
is a historical text that categorizes and chronologizes the events listed in the ''Six National Histories''. It was compiled by Sugawara no Michizane and completed in 892. The text was commissioned by Emperor Uda. Contents The text was originally 200 volumes in length with two indexes and three genealogical volumes. However, much of it was lost during the Ōnin War in the late 15th century. Only 62 volumes are currently extant: volumes 1-5, 8-11, 14-16, 19, 25, 28, 31-36, 40, 54, 61, 66, 71-75, 77-80, 83-84, 86-89, 99, 101, 107, 147, 159, 165, 170-171, 173, 177-180, 182, 185-187, 189-190, 193-194, 199.Nihon Koten Bungaku Daijiten (1986:1938) The text categories and subcategories the historical accounts given in the ''Six National Histories'', listing each of which in chronological order..Koten Bungaku Jiten (1997:1507) There are a total of eighteen categories, with another five lost in the missing volumes. While the final national history, ''Nihon Sandai Jitsuroku'', was complet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1855 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, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Kantō Earthquakes
South Kantō earthquakes () or Greater Tokyo Area earthquakes () are general terms for major earthquakes that occurs repeatedly historically in the southern part of Kanto region (Tokyo, Kanagawa, Chiba, Saitama, etc., Greater Tokyo Area) in Japan. It has been announced that there is a 70% chance that earthquakes of about M7 will occur in the southern part of the Kanto region within the next 30 years. Tokyo (Greater Tokyo Area) is one of the largest cities in the world (populated area), if a large earthquake occurs in the southern part of the Kanto region, the damage is expected to be enormous. And also, indirect damage caused by the earthquake is thought to extend to the entire world for a long period of time. It has been announced that if a large earthquake occurs in the Greater Tokyo Area, it would kill 23,000 people in the worst case scenario. Major earthquakes in the past This is a list of major earthquakes that have caused damage to the southern part of the Kanto region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Earthquakes In Japan
This is a list of earthquakes in Japan with either a magnitude greater than or equal to 7.0 or which caused significant damage or casualties. As indicated below, magnitude is measured on the Richter magnitude scale (''ML'') or the moment magnitude scale (''Mw''), or the surface wave magnitude scale (''Ms'') for very old earthquakes. The present list is not exhaustive, and furthermore reliable and precise magnitude data is scarce for earthquakes that occurred before the development of modern measuring instruments. History Although there is mention of an earthquake in Yamato in what is now Nara Prefecture on August 23, 416, the first earthquake to be reliably documented took place in Nara prefecture on May 28, 599 during the reign of Empress Suiko, destroying buildings throughout Yamato province.Hammer, Joshua. (2006). ''Yokohama Burning: The Deadly 1923 Earthquake and Fire that Helped Forge the Path to World War II,'' p. 62–63.Ishibashi, K. (2004);Status of historical seismolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nankai Megathrust Earthquakes
Nankai megathrust earthquakes are great megathrust earthquakes that occur along the ''Nankai megathrust'' – the fault under the Nankai Trough – which forms the plate interface between the subducting Philippine Sea Plate and the overriding Amurian Plate (part of the Eurasian Plate), which dips beneath southwestern Honshu, Japan. The fault is divided into five segments in three zones, which rupture separately or in combination, and depending on location, the resulting earthquakes are subdivided by zone from west to east into Nankai earthquakes, Tōnankai earthquakes, and Tōkai earthquakes. The earthquakes occur with a return period of about 90–200 years, and often occur in pairs, where a rupture along one part of the fault is followed by a rupture elsewhere on the fault, notably the 1854 Ansei-Tōkai earthquake and the 1854 Ansei-Nankai earthquake the next day, and the 1944 Tōnankai earthquake, followed by the 1946 Nankaidō earthquake. In one recorded case (the 1707 Hōe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the coastal areas of the former provinces of Rikuō in Aomori, Rikuchū in Aomori, and Rikuzen in Miyagi. The irregular ria coastline and its many bays tend to amplify the destructiveness of tsunami waves which reach the shores of Sanriku, as demonstrated in the damage caused by the 2011 Tōhoku earthquake and tsunami. History The Sanriku coast has a well-documented history of significant seismic activity. A major earthquake in the 19th century caused more than 20,000 deaths, and another in the 20th century caused thousands more. The recurrence of major seismic activity continues in the 21st century. Ancient There is geological evidence, uncovered after the latest tsunami event of 2011, of six catastrophic tsunamis hitting the Sanriku co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
