1.
Sanriku Coast
–
The name comes from the historical region of Sanriku, referring to the former provinces of Rikuō, Rikuchū and Rikuzen. There are the Tanesashi Coast, the Rikuchu Kaigan National Park, the bays of this ria coastline tend to amplify the destructiveness of tsunami waves. The 2011 disaster created a new baseline for analysis of regularly occurring tsunamis, tōhoku region Tōsandō Sanriku, Iwate Sanriku Railway
2.
Japan Standard Time
–
Japan Standard Time or JST is the standard timezone in Japan, and is 9 hours ahead of UTC, i. e. it is UTC+09,00. There is no daylight saving time, though its introduction has been debated several times, during World War II, it was often called Tokyo Standard Time. Japan Standard Time is the same as Korean Standard Time, Indonesian Eastern Standard Time, before the Meiji era, each local region had its own timezone in which noon was when the sun was exactly at its zenith. As modern transportation methods, such as trains, were adopted, in 1886, Ordinance 51 was issued in response to this problem, which stated, Ordinance 51 - July 13,1886 The prime meridian passes through Englands Greenwich Observatory. Longitudes are calculated using the prime meridian, counting 180 degrees either east or west, positive degrees are east, negative degrees are west. On January 1,1888,135 degrees east longitude will be set as the meridian for all of Japan. According to this, the time was set 9 hours ahead of GMT. In the ordinance, the first clause mentions GMT, the second defines east longitude and west longitude, the city of Akashi in Hyōgo Prefecture is located exactly on 135 degrees east longitude and subsequently became known as Toki no machi. While Korea came under Japanese rule in 1910, Korea Standard Time of UTC+8,30 continued to be used until 1912, when it was changed to Central Standard Time. Western Standard Time, which was used in Taiwan and some parts of Okinawa, was abolished by Ordinance 529 in 1937 and replaced by Central Standard Time in those areas. Territories occupied by Japan during World War II, including Singapore and Malaya, adopted Japan Standard Time for the duration of their occupation, more recently there have been efforts to bring back DST in Japan, but so far this has not happened. The two-time-zone system was implemented in Japan between January 1896 and September 1937, From October 1937, Central Standard Time was also used in western Okinawa, the IANA time zone database contains one zone for Japan in the file zone. tab, named Asia/Tokyo. From 1948–51, Japan observed DST between May and September every year under an initiative of the U. S. -led occupation army, since then, DST has never been officially implemented nationwide in Japan. Starting in the late 1990s, a movement to reinstate DST in Japan gained some popularity, aiming at saving energy, in the early 2000s, a few local governments and commerce departments promoted unmandated hour-earlier work schedule experiments during the summer without officially resetting clocks. The Council on Economic and Fiscal Policy is expected to propose that the Japanese government begin studying DST in an attempt to combat global warming. Japanese PM Shinzo Abe made a significant effort to introduce daylight saving time, however, it is not clear that DST would conserve energy in Japan. JJY Japanese calendar UTC+09,00 Japanese clock
3.
Geographic coordinate system
–
A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
4.
Japan
–
Japan is a sovereign island nation in Eastern Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asia Mainland and stretches from the Sea of Okhotsk in the north to the East China Sea, the kanji that make up Japans name mean sun origin. 日 can be read as ni and means sun while 本 can be read as hon, or pon, Japan is often referred to by the famous epithet Land of the Rising Sun in reference to its Japanese name. Japan is an archipelago consisting of about 6,852 islands. The four largest are Honshu, Hokkaido, Kyushu and Shikoku, the country is divided into 47 prefectures in eight regions. Hokkaido being the northernmost prefecture and Okinawa being the southernmost one, the population of 127 million is the worlds tenth largest. Japanese people make up 98. 5% of Japans total population, approximately 9.1 million people live in the city of Tokyo, the capital of Japan. Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period, the first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other regions, mainly China, followed by periods of isolation, from the 12th century until 1868, Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor. Japan entered into a period of isolation in the early 17th century. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the bombings of Hiroshima and Nagasaki. Japan is a member of the UN, the OECD, the G7, the G8, the country has the worlds third-largest economy by nominal GDP and the worlds fourth-largest economy by purchasing power parity. It is also the worlds fourth-largest exporter and fourth-largest importer, although Japan has officially renounced its right to declare war, it maintains a modern military with the worlds eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a country with a very high standard of living. Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world, in ancient China, Japan was called Wo 倭. It was mentioned in the third century Chinese historical text Records of the Three Kingdoms in the section for the Wei kingdom, Wa became disliked because it has the connotation of the character 矮, meaning dwarf. The 倭 kanji has been replaced with the homophone Wa, meaning harmony, the Japanese word for Japan is 日本, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, at the start of the seventh century, a delegation from Japan introduced their country as Nihon
5.
United States
–
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
6.
Kesen District, Iwate
–
Kesen is a district in Iwate Prefecture, Japan and consists of the town of Sumita. Sumita is small community which borders the cities of Ōfunato and Rikuzentakata. Nearly 90 percent of Sumita is forested, the economic base is largely agricultural and forestry-related. Its population was listed at 5,952 residents as of January,2014, kesen District has a total area is 334.83 km². Sumita
7.
Iwate Prefecture
–
Iwate Prefecture is a prefecture of Japan. It is located in the Tōhoku region of Honshu island and contains the islands easternmost point, Iwate has the lowest population density of any prefecture outside Hokkaido. There are several theories about the origin of the name Iwate, but the most well known is the tale Oni no tegata and these rocks are said to have been thrown down into Morioka by an eruption of Mt. Iwate. According to the legend, there was once a devil who often tormented and harassed the local people, when the people prayed to the spirits of Mitsuishi for protection, the devil was immediately shackled to these rocks and forced to make a promise never to trouble the people again. As a seal of his oath the devil made a handprint on one of the rocks, thus giving rise to the name Iwate, even now after a rainfall it is said that the devils hand print can still be seen there. Bashō visited and wrote about Iwate in the journey described in Oku no Hosomichi and he was especially inspired by Hiraizumi. Until the Meiji Restoration, the area of Iwate prefecture was part of Mutsu Province, Iwate Prefecture was created in 1876 in the aftermath of the Boshin Civil War which heralded the beginning of the Meiji Restoration. The area now known as Iwate Prefecture was inhabited by the Jomon people who left their artifacts throughout the prefecture, for example, a large number of burial pits from the Middle Jomon Period have been found in Nishida. Various sites from the Late Jomon Period including Tateishi, Makumae and Hatten contain clay figurines, masks and ear, the Kunenbashi site in Kitakami City has yielded stone swords, tablets and tools as well as clay figurines, earrings and potsherds from the Final Jomon Period. The earliest mention of a Japanese presence dates to about 630 when the Hakusan Shrine was said to have built on Mt. Kanzan in what is now Hiraizumi. At this time various Japanese traders, hunters, adventurers, priests, in 712 the province of Mutsu, containing all of Tohoku, was divided into Dewa Province, the area west of the Ou Mountains and Mutsu Province. In 729 Kokuseki-ji Temple was founded in what is now Mizusawa Ward, More fighting occurred the next and following years but mostly in Dewa and the area south of present-day Iwate prefecture. This situation continued until March 787 when the Yamato army suffered a defeat in the Battle of Sufuse Village in what is now Mizusawa Ward. There the Emishi leaders More and Aterui leading a cavalry force trapped the Yamato infantry. Over 1,000 soldiers drowned that day, the Japanese general Ki no Asami Kosami was rebuked by the Emperor Kanmu when he returned to Kyoto. Since the Japanese could not win on the battlefield they resorted to means to conquer the Emishi. Trade for superior quality iron wares and sake made the Emishi dependent on the Japanese for these valuable goods, bribes were offered to the Emishi leaders in the form of Japanese citizenship and rank if they would defect. Finally a campaign of burning crops and kidnapping the Emishi women and children, many a stout warrior gave up the fight to join his family again
8.
Honshu
–
Honshu is the largest and most populous island of Japan, located south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Straits. The island separates the Sea of Japan, which lies to its north and west, from the North Pacific Ocean to its south and it is the seventh-largest island in the world, and the second-most populous after the Indonesian island of Java. Honshu had a population of 103 million as of 2005, mostly concentrated in the coastal lowlands, as the historical center of Japanese culture and political power, the island includes several past Japanese capitals, including Kyoto, Nara, and Kamakura. Much of the southern shore forms part of the Taiheiyō Belt. The island is linked to the three major Japanese islands by a number of bridges and tunnels. Its climate is humid and mild, the island is roughly 1,300 km long and ranges from 50 to 230 km wide, and its total area is 225,800 km2, 60% of the total area of Japan, making it slightly larger than Great Britain. Its land area has been increasing with land reclamation and coastal uplift in the north, Honshu has 5,450 kilometres of coastline. Mountainous and volcanic, Honshu experiences frequent earthquakes, the highest peak is the active volcano Mount Fuji at 3,776 m, which makes Honshu the worlds 7th highest island. There are many rivers, including the Shinano River, Japans longest, the northernmost point on Honshu is the tip of the Shimokita Peninsula in Ōma, Aomori, Cape Kure lies at the southern extreme in Kushimoto, Wakayama. The islands eastern extremity is Todogasaki in Miyako, Iwate, and its western one is Bishanohana in Shimonoseki, Honshu spans more than eight degrees of latitude and 11 degrees of longitude. Honshu is connected to the islands of Hokkaido, Kyushu and Shikoku by tunnels or bridges, the island is divided into five nominal regions and contains 34 prefectures, including metropolitan Tokyo. Administratively, some islands are included within these prefectures, notably including the Ogasawara Islands, Sado Island, Izu Ōshima. Fruits, vegetables, grains, rice and cotton are grown in Honshu, niigata is noted as an important producer of rice. The Kantō and Nōbi plains produce rice and vegetables, yamanashi is a major fruit-growing area, and Aomori is famous for its apples. Rare species of the lichen genus Menegazzia are found only in Honshu, yields of zinc, copper, and oil have been found on Honshu
9.
Tsunami
–
A tsunami or tidal wave, also known as a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Unlike normal ocean waves which are generated by wind, or tides which are generated by the pull of the Moon and Sun. Tsunami waves do not resemble normal undersea currents or sea waves, Tsunamis generally consist of a series of waves with periods ranging from minutes to hours, arriving in a so-called internal wave train. Wave heights of tens of metres can be generated by large events, numerous terms are used in the English language to describe waves created in a body of water by the displacement of water, however, none of the terms in frequent use are entirely accurate. The term tsunami, meaning harbour wave in literal translation, comes from the Japanese 津波, while not entirely accurate, as tsunami are not restricted to harbours, tsunami is currently the term most widely accepted by geologists and oceanographers. Tsunami are sometimes referred to as tidal waves and this once-popular term derives from the most common appearance of tsunami, which is that of an extraordinarily high tidal bore. Although the meanings of tidal include resembling or having the form or character of the tides, use of the tidal wave is discouraged by geologists. The term seismic sea wave also is used to refer to the phenomenon, prior to the rise of the use of the term tsunami in English-speaking countries, scientists generally encouraged the use of the term seismic sea wave rather than tidal wave. The Sumatran region is not unused to tsunamis either, with earthquakes of varying magnitudes regularly occurring off the coast of the island, Tsunamis are an often underestimated hazard in the Mediterranean Sea and parts of Europe. The tsunami claimed more than 123,000 lives in Sicily, the Storegga Slide in the Norwegian sea and some examples of tsunamis affecting the British Isles refer to landslide and meteotsunamis predominantly and less to earthquake-induced waves. The cause, in my opinion, of this phenomenon must be sought in the earthquake, at the point where its shock has been the most violent the sea is driven back, and suddenly recoiling with redoubled force, causes the inundation. Without an earthquake I do not see how such an accident could happen, the principal generation mechanism of a tsunami is the displacement of a substantial volume of water or perturbation of the sea. This displacement of water is attributed to either earthquakes, landslides, volcanic eruptions, glacier calvings or more rarely by meteorites. The waves formed in this way are then sustained by gravity, tides do not play any part in the generation of tsunamis. Tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water and they grow in height when they reach shallower water, in a wave shoaling process described below. A tsunami can occur in any state and even at low tide can still inundate coastal areas. On April 1,1946, the 8.6 Mw Aleutian Islands earthquake occurred with a maximum Mercalli intensity of VI and it generated a tsunami which inundated Hilo on the island of Hawaii with a 14-metre high surge. Between 165 and 173 were killed, the area where the earthquake occurred is where the Pacific Ocean floor is subducting under Alaska
10.
Japan Trench
–
The Japan Trench is an oceanic trench, a part of the Pacific Ring of Fire, in the floor of the northern Pacific Ocean off northeast Japan. It extends from the Kuril Islands to the Bonin Islands and is 10,554 metres at its deepest and it is an extension of the Kuril-Kamchatka Trench to the north and the Izu-Ogasawara Trench to its south with a length of 800 km. This trench is created when the oceanic Pacific plate subducts beneath the continental Okhotsk Plate, the subduction process causes bending of the downgoing plate, creating a deep-sea trench. On 11 August 1989, the Shinkai 6500 three-person submersible descended to 6,526 m while exploring the Japan Trench. In October 2008, a UK-Japan team discovered a shoal of fish, Pseudoliparis amblystomopsis at a depth of 7,700 m in the trench, the Bathyscaphe Trieste observed bottom-dwelling fish at the base of the Marianas Trench/Challenger deep at 10,916 m. Oceanic trench Pacific Ring of Fire Northeastern Japan Arc Izu-Bonin-Mariana Arc Notes Media related to Japan Trench at Wikimedia Commons
11.
Subduction
–
Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced or sinks due to gravity into the mantle. Regions where this occurs are known as subduction zones. Rates of subduction are typically in centimeters per year, with the rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Plates include both oceanic crust and continental crust, stable subduction zones involve the oceanic lithosphere of one plate sliding beneath the continental or oceanic lithosphere of another plate due to the higher density of the oceanic lithosphere. That is, the lithosphere is always oceanic while the overriding lithosphere may or may not be oceanic. Subduction zones are sites that have a rate of volcanism, earthquakes. Subduction zones are sites of convective downwelling of Earths lithosphere, subduction zones exist at convergent plate boundaries where one plate of oceanic lithosphere converges with another plate. The descending slab, the plate, is over-ridden by the leading edge of the other plate. The slab sinks at an angle of approximately twenty-five to forty-five degrees to Earths surface and this sinking is driven by the temperature difference between the subducting oceanic lithosphere and the surrounding mantle asthenosphere, as the colder oceanic lithosphere is, on average, denser. At a depth of approximately 80–120 kilometers, the basalt of the oceanic crust is converted to a rock called eclogite. At that point, the density of the oceanic crust increases and provides additional negative buoyancy and it is at subduction zones that Earths lithosphere, oceanic crust, sedimentary layers and some trapped water are recycled into the deep mantle. Earth is so far the only planet where subduction is known to occur, subduction is the driving force behind plate tectonics, and without it, plate tectonics could not occur. Subduction zones dive down into the mantle beneath 55,000 kilometers of convergent plate margins, subduction zones burrow deeply but are imperfectly camouflaged, and geophysics and geochemistry can be used to study them. Not surprisingly, the shallowest portions of subduction zones are known best, subduction zones are strongly asymmetric for the first several hundred kilometers of their descent. They start to go down at oceanic trenches and their descents are marked by inclined zones of earthquakes that dip away from the trench beneath the volcanoes and extend down to the 660-kilometer discontinuity. Subduction zones are defined by the array of earthquakes known as the Wadati–Benioff zone after the two scientists who first identified this distinctive aspect. Subduction zone earthquakes occur at greater depths than elsewhere on Earth, such deep earthquakes may be driven by deep phase transformations, thermal runaway, the subducting basalt and sediment are normally rich in hydrous minerals and clays. Additionally, large quantities of water are introduced into cracks and fractures created as the slab bends downward
12.
Convergent boundary
–
As a result of pressure, friction, and plate material melting in the mantle, earthquakes and volcanoes are common near convergent boundaries. When two plates move towards one another, they form either a subduction zone or a continental collision and this depends on the nature of the plates involved. In a subduction zone, the plate, which is normally a plate with oceanic crust, moves beneath the other plate. During collisions between two plates, large mountain ranges, such as the Himalayas are formed. The nature of a convergent boundary depends on the type of plates that are colliding, at an oceanic-continental convergent boundary, the oceanic lithosphere will always subduct below the continental lithosphere. This is caused by the density difference between the oceanic and continental lithosphere. This type of boundary is called a subduction zone. At the surface, the expression is commonly an oceanic trench which forms on the oceanic side. On the continental side, a chain of volcanoes forms above the location of the subducting plate, an example of a continental-oceanic subduction zone is the area along the western coast of South America where the oceanic Nazca Plate is being subducted beneath the continental South American Plate. A volcanic arc is formed on the plate, above the location of the downgoing oceanic slab. The volcanic arc is the expression of the magma that is generated by hydrous melting of the mantle above the downgoing slab. The buoyant fluids then rise into the asthenosphere, where they lower the temperature of the mantle. Either action will create extensive mountain ranges and it may have also pushed nearby parts of the Asian continent aside to the east. When two plates with oceanic crust converge, they create an island arc as one plate is subducted below the other. The arc is formed from volcanoes which erupt through the plate as the descending plate melts below it. The arc shape occurs because of the surface of the earth. A deep oceanic trench is located in front of such arcs where the descending slab dips downward, plates may collide at an oblique angle rather than head-on to each other, and this may cause strike-slip faulting along the collision zone, in addition to subduction or compression. Not all plate boundaries are easily defined, some are broad belts whose movements are unclear to scientists
13.
Pacific Plate
–
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate, the Pacific Plate contains an interior hot spot forming the Hawaiian Islands. Hillis and Müller are reported to consider the Birds Head Plate to be moving in unison with the Pacific Plate, bird considers them to be unconnected. The north-eastern side is a divergent boundary with the Explorer Plate, the Juan de Fuca Plate and the Gorda Plate forming respectively the Explorer Ridge, the Juan de Fuca Ridge and the Gorda Ridge. In the middle of the side is a transform boundary with the North American Plate along the San Andreas Fault. The south-eastern side is a divergent boundary with the Nazca Plate forming the East Pacific Rise, the southern side is a divergent boundary with the Antarctic Plate forming the Pacific-Antarctic Ridge. The Alpine Fault marks a boundary between the two plates, and further south the Indo-Australian Plate subducts under the Pacific Plate forming the Puysegur Trench. The southern part of Zealandia, which is to the east of this boundary, is the plates largest block of continental crust, the northern side is a convergent boundary subducting under the North American Plate forming the Aleutian Trench and the corresponding Aleutian Islands. The Pacific Plate is almost entirely oceanic crust, but it contains some continental crust in New Zealand, Baja California, the Pacific Plate has the distinction of showing one of the largest areal sections of the oldest members of seabed geology being entrenched into eastern Asian oceanic trenches. The oldest member disappearing by way of the Plate Tectonics cycle is early-Cretaceous, all maps of the Earths ocean floor geology show ages younger than 145 million years, only about 1/30 of the Earths 4.55 billion year history
14.
Eurasian Plate
–
It also includes oceanic crust extending westward to the Mid-Atlantic Ridge and northward to the Gakkel Ridge. The eastern side is a boundary with the North American Plate to the north and a boundary with the Philippine Sea Plate to the south, and possibly with the Okhotsk Plate and the Amurian Plate. The southerly side is a boundary with the African Plate to the west, the Arabian Plate in the middle, the westerly side is a divergent boundary with the North American Plate forming the northernmost part of the Mid-Atlantic Ridge, which is straddled by Iceland. The geodynamics of central Asia is dominated by the interaction between the Eurasian and Indian Plates, in this area, many subplates or crust blocks have been recognized, which form the Central Asian and the East Asian transit zones
15.
Accretionary wedge
–
An accretionary wedge or accretionary prism forms from sediments accreted onto the non-subducting tectonic plate at a convergent plate boundary. Accretionary wedges and accreted terranes are not equivalent to tectonic plates, material exposed in the forearc ridge may include fragments of oceanic crust or high pressure *, metamorphic rocks thrust from deeper in the subduction zone. The piecemeal addition of these accreted terranes has added an average of 600 km in width along the margin of the North American continent. The topographic expression of the accretionary wedge forms a lip, which may dam basins of accumulated materials that, otherwise, Accretionary wedges are the home of mélange, intensely deformed packages of rocks that lack coherent internal layering and coherent internal order. The internal structure of a wedge is similar to that found in a thin-skinned foreland thrust belt. A series of thrusts verging towards the trench are formed with the youngest most outboard structures progressively uplifting the older more inboard thrusts. The shape of the wedge is determined by how readily the wedge will fail along its basal decollement and in its interior and this failure will result in a mature wedge that has an equilibrium triangular cross-sectional shape of a critical taper. Once the wedge reaches a critical taper, it will maintain that geometry, the small sections of oceanic crust that are thrust over the overriding plate are said to be obducted. Where this occurs, rare slices of ocean crust, known as ophiolites, are preserved on land and they provide a valuable natural laboratory for studying the composition and character of the oceanic crust and the mechanisms of their emplacement and preservation on land. A classic example is the Coast Range ophiolite of California, which is one of the most extensive ophiolite terranes in North America. This oceanic crust likely formed during the middle Jurassic Period, roughly 170 million years ago and it was later accreted to the continental margin of Laurasia. The existence of the South China Sea slope also leads the strike of impinging folds with NNW-trend to turn sharply to a NE-strike. In accretionary wedges, seismicity activating superimposed thrusts may drive methane, mechanical models that treat accretionary complexes as critically tapered wedges of sediment demonstrate that pore pressure controls their taper angle by modifying basal and internal shear strength. Results from some studies show that pore pressure in accretionary wedges can be viewed as a dynamically maintained response to factors which drive pore pressure, sediment permeability and incoming sediment thickness are the most important factors, whereas fault permeability and the partitioning of sediment have a small effect. With increased sediment thickness, increased pore pressure drives a decrease in stable taper angle from 8. 4°–12. 5° to <2. 5–5°, observations from active margins also indicate a strong trend of decreasing taper angle with increased sediment thickness. Rapid tectonic loading of wet sediment in accretionary wedges is likely to cause the pressure to rise until it is sufficient to cause dilatant fracturing. Dewatering of sediment that has been underthrust and accreted beneath the wedge can produce a steady supply of such highly overpressured fluid. This in turn buffers the strength of the wedge at the strength, which is not pressure‐dependent
16.
Shinto
–
Shinto practices were first recorded and codified in the written historical records of the Kojiki and Nihon Shoki in the 8th century. Still, these earliest Japanese writings do not refer to a unified Shinto religion, practitioners express their diverse beliefs through a standard language and practice, adopting a similar style in dress and ritual, dating from around the time of the Nara and Heian periods. The word Shinto was adopted, originally as Jindō or Shindō, from the written Chinese Shendao, the oldest recorded usage of the word Shindo is from the second half of the 6th century. Kami are defined in English as spirits, essences or gods, Kami and people are not separate, they exist within the same world and share its interrelated complexity. Shinto is the largest religion in Japan, practiced by nearly 80% of the population, Shinto has 81,000 shrines and 85,000 priests in the country. According to Inoue, In modern scholarship, the term is used with reference to kami worship and related theologies, rituals. In these contexts, Shinto takes on the meaning of Japans traditional religion, as opposed to religions such as Christianity, Buddhism, Islam. Shinto religious expressions have been distinguished by scholars into a series of categories, Shrine Shinto and it consists in taking part in worship practices and events at local shrines. Before the Meiji Restoration, shrines were disorganized institutions usually attached to Buddhist temples, the current successor to the imperial organization system, the Association of Shinto Shrines, oversees about 80,000 shrines nationwide. Folk Shinto includes the folk beliefs in deities and spirits. Practices include divination, spirit possession, and shamanic healing, some of their practices come from Buddhism, Taoism or Confucianism, but most come from ancient local traditions. Sect Shinto is a designation originally created in the 1890s to separate government-owned shrines from local organised religious communities. These communities originated especially in the Edo period, the basic difference between Shrine Shinto and Sect Shinto is that sects are a later development and grew self-consciously. They can identify a founder, a set of teachings. Sect Shinto groups are thirteen, and usually classified under five headings, pure Shinto sects, Confucian sects, mountain worship sects, purification sects, and faith-healing sects. Koshintō, literally Old Shinto, is a reconstructed Shinto from before the time of Buddhism, today based on Ainu religion and it continues the restoration movement begun by Hirata Atsutane. Many other sects and schools can be distinguished, Kami or shin is defined in English as god, spirit, spiritual essence, all these terms meaning the energy generating a thing. Since the Japanese language does not distinguish between singular and plural, kami refers to the divinity, or sacred essence, that manifests in multiple forms, rocks, trees, rivers, animals, places, and even people can be said to possess the nature of kami
17.
First Sino-Japanese War
–
The First Sino-Japanese War was fought between the Qing Empire of China and the Empire of Japan, primarily over influence of Korea. After more than six months of unbroken successes by Japanese land and naval forces and the loss of the Chinese port of Weihaiwei, the Qing government sued for peace in February 1895. The war demonstrated the failure of the Qing Empires attempts to modernize its military and fend off threats to its sovereignty, especially when compared with Japans successful Meiji Restoration. For the first time, regional dominance in East Asia shifted from China to Japan, the humiliating loss of Korea as a tributary state sparked an unprecedented public outcry. Within China, the defeat was a catalyst for a series of political upheavals led by Sun Yat-sen and Kang Youwei, the war is commonly known in China as the War of Jiawu, referring to the year as named under the traditional sexagenary system of years. In Japan, it is called the Japan–Qing War, in Korea, where much of the war took place, it is called the Qing–Japan War. After two centuries, the Japanese policy of seclusion under the shoguns of the Edo period came to an end when the country was forced open to trade by British and American intervention in 1854. The years following the Meiji Restoration of 1868 and the fall of the Shogunate had seen Japan transform itself from a society into a modern industrial state. The Japanese had sent delegations and students around the world to learn and assimilate Western arts and sciences, Korea continued to try to exclude foreigners, refusing embassies from foreign countries and firing on ships near its shores. At the start of the war, Japan had the benefit of three decades of reform, leaving Korea outdated and vulnerable, as a newly risen power, Japan turned its attention toward its neighbor, Korea. Japan wanted to block any other power from annexing or dominating Korea, as Prussian advisor Major Klemens Meckel put it to the Japanese, Korea was a dagger pointed at the heart of Japan. On February 27,1876, after confrontations between Korean isolationists and Japanese, Japan imposed the Japan–Korea Treaty of 1876, forcing Korea open to Japanese trade. Similar treaties were signed between Korea and other nations, Korea had traditionally been a tributary state of Chinas Qing Empire, which exerted large influence over the conservative Korean officials who gathered around the royal family of the Joseon kingdom. Opinion in Korea itself was split, conservatives wanted to retain the traditional relationship under China, while reformists wanted to approach Japan and Western nations. After fighting two Opium Wars against the British in 1839 and 1856, and another war against the French in 1885, Japan saw the opportunity to take Chinas place in the strategically vital Korea. In 1882, the Korean peninsula experienced a drought which led to food shortages, causing much hardship. Korea was on the verge of bankruptcy, even falling months behind on military pay, on July 23, a military mutiny and riot broke out in Seoul in which troops, assisted by the population, sacked the rice granaries. The next morning, the crowd attacked the palace and barracks
18.
Miyagi Prefecture
–
Miyagi Prefecture is a prefecture of Japan in the Tōhoku region on Honshu island. Miyagi Prefecture was formerly part of the province of Mutsu, Mutsu Province, on northern Honshu, was one of the last provinces to be formed as land was taken from the indigenous Emishi, and became the largest as it expanded northward. The ancient capital was at Taga-jō in modern Miyagi Prefecture, in the third month of second year of the Wadō era, there was an uprising against governmental authority in Mutsu Province and in nearby Echigo Province. Troops were promptly dispatched to subdue the revolt, in Wadō5, the land of Mutsu Province was administratively separated from Dewa Province. During the Sengoku period various clans ruled different parts of the province, in the Meiji period, four new provinces were created from parts of Mutsu, Rikuchū, Rikuzen, Iwaki, and Iwashiro. The area that is now Aomori Prefecture continued to be part of Mutsu until the abolition of the han system, Date Masamune built a castle at Sendai as his seat to rule Mutsu. In 1871, Sendai Prefecture was formed and it was renamed Miyagi prefecture the following year. On March 11,2011, a 9.0 magnitude earthquake, the tsunami was estimated to be approximately 10 meters high in Miyagi Prefecture. On April 7,2011,7. 4-magnitude earthquake strikes off coast of Miyagi, Japan, workers were then evacuated from the nearby troubled Fukushima-Daiichi nuclear facility once again, as a tsunami warning was issued for the coastline. Residents were told to flee for inner land at this time, officials from the U. S. Geological Survey later downgraded the magnitude to 7.1 from 7.4. In 2013, Crown Prince Naruhito and Crown Princess Masako visited the prefecture to see the progress made since the tsunami, Miyagi Prefecture is in the central part of Tōhoku, facing the Pacific Ocean, and contains Tōhokus largest city, Sendai. There are high mountains on the west and along the northeast coast, matsushima is known as one of the three most scenic views of Japan, with a bay full of 260 small islands covered in pine groves. Oshika Peninsula projects from the coastline of the prefecture. Fourteen cities are located in Miyagi Prefecture, Sendai - the largest, as of March 2011, the prefecture produced 4. 7% of Japans rice, 23% of oysters, and 15. 9% of sauries. In July 2011, the Japanese government decided to ban all shipments of cattle from northeast Miyagi Prefecture over fears of radioactive contamination. Matsushima Bay Sendai Airport The sports teams listed below are based in Miyagi Prefecture, baseball Tohoku Rakuten Golden Eagles Tohoku Reia Football Vegalta Sendai Sony Sendai F. C. Sendai was the castle town of the daimyo Date Masamune. The remains of Sendai Castle stand on a hill above the city, Miyagi Prefecture boasts one of Japans three greatest sights. Matsushima, the islands, dot the waters off the coast of the prefecture
19.
Aomori Prefecture
–
Aomori Prefecture is a prefecture of Japan located in the Tōhoku region. The capital is the city of Aomori, until the Meiji Restoration, the area of Aomori prefecture was known as the northern part of Mutsu Province. During the Edo period the Hirosaki clan began building a seaport at the current city of Aomori, there were green woods near the city which were used as landmarks for the ships that came into port. These green woods called aoi-mori is where Aomori got its name, the prefecture came into existence in 1871. The town of Aomori was established in 1889, the town was incorporated as a city in 1898 with a population of 28,000. On May 3,1910 a fire out in the Yasukata district. Fanned by strong winds, the fire devastated the whole city. The conflagration claimed 26 lives and injured a further 160 residents and it destroyed 5,246 houses and burnt 19 storage sheds and 157 warehouses. At 10,30 p. m. on July 28,1945 a squadron of American B29 bombers bombed over 90% of the city, radio Aomori made its first broadcast in 1951. Four years later, the first fish auctions were held,1958 saw the completion of the Municipal Fish Market as well as the opening of the Citizens Hospital. In the same year, the Tsugaru Line established a connection with Minmaya Village at the tip of the peninsula. Various outlying towns and villages were incorporated into the city and with the absorption of Nonai Village in 1962. Almost exactly three years later, on March 13, railroad service was inaugurated on the Tsugaru Kaikyo Line and that same day saw the end of the Seikan Ferry service. During their 80 years of service, the ferries of the Seikan line sailed between Aomori and Hakodate some 720,000 times, carrying 160 million passengers. In April 1993, Aomori Public College opened, in August 1994, Aomori City made an Education, Culture and Friendship Exchange Pact with Kecskemét in Hungary. One year later a treaty was signed with Pyongtaek in South Korea. In April 1995, Aomori Airport began offering regular international air service to Seoul, South Korea, and Khabarovsk, Russia. In June 2007, four North Korean defectors reached Aomori Prefecture, after having been at sea for six days, in March 2011, a magnitude 9.0 earthquake struck Japan on the east coast
20.
Hokkaido
–
Hokkaido, formerly known as Ezo, Yezo, Yeso, or Yesso, is the second largest island of Japan, and the largest and northernmost prefecture. The Tsugaru Strait separates Hokkaido from Honshu, the two islands are connected by the underwater railway Seikan Tunnel. The largest city on Hokkaido is its capital, Sapporo, which is also its only ordinance-designated city, about 43 km north of Hokkaido lies Sakhalin island, Russia, whereas to its east and north-east are the disputed Kuril Islands. Hokkaido was settled by the Ainu, Nivkh, and Orok before recorded history, the Nihon Shoki, finished in 720 AD, is often said to be the first mention of Hokkaido in recorded history. According to the text, Abe no Hirafu led a navy and army to northern areas from 658 to 660 and came into contact with the Mishihase. One of the places Hirafu went to was called Watarishima, which is believed to be present-day Hokkaido. During the Nara and Heian periods, people in Hokkaido conducted trade with Dewa Province, from the Middle Ages, the people in Hokkaido began to be called Ezo. Hokkaido, formerly known as Ezochi Ezochi or Ezogashima, the Ezo mainly relied upon hunting and fishing and obtained rice and iron through trade with the Japanese. During the Muromachi period, the Japanese created a settlement at the south of the Oshima Peninsula, as more people moved to the settlement to avoid battles, disputes arose between the Japanese and the Ainu. The disputes eventually developed into a war, takeda Nobuhiro killed the Ainu leader, Koshamain, and defeated the opposition in 1457. Nobuhiros descendants became the rulers of the Matsumae-han, which was granted trading rights with the Ainu in the Azuchi-Momoyama. The Matsumae familys economy relied upon trade with the Ainu and they held authority over the south of Ezochi until the end of the Edo period in 1868. The Matsumae clan rule over the Ainu must be understood in the context of the expansion of the Japanese feudal state, medieval military leaders in northern Honshū maintained only tenuous political and cultural ties to the imperial court and its proxies, the Kamakura Shogunate and Ashikaga Shogunate. Feudal strongmen sometimes located themselves within medieval institutional order, taking shogunal titles, in fact many of the feudal strongmen were descended from Emishi military leaders who had been assimilated into Japanese society. The Matsumae clan were of Yamato descent like other ethnic Japanese people, the Emishi were conquered and integrated into the Japanese state dating back as far as the 8th century, and as result began to lose their distinctive culture and ethnicity as they became minorities. By the time the Matsumae clan ruled over the Ainu most of the Emishi were ethnically mixed, there were numerous revolts by the Ainu against feudal rule. The last large-scale resistance was Shakushains Revolt in 1669–1672, in 1789, a smaller movement, the Menashi-Kunashir Rebellion, was also crushed. After that rebellion the terms Japanese and Ainu referred to clearly distinguished groups, in 1799–1821 and 1855–1858 the Edo Shogunate took direct control over Hokkaido in response to a perceived threat from Russia
21.
Hawaii
–
Hawaii is the 50th and most recent state to have joined the United States of America, having received statehood on August 21,1959. Hawaii is the only U. S. state located in Oceania and it is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean. Hawaii is the only U. S. state not located in the Americas, the state encompasses nearly the entire volcanic Hawaiian archipelago, which comprises hundreds of islands spread over 1,500 miles. At the southeastern end of the archipelago, the eight main islands are—in order from northwest to southeast, Niʻihau, Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Kahoʻolawe, Maui, and the Island of Hawaiʻi. The last is the largest island in the group, it is called the Big Island or Hawaiʻi Island to avoid confusion with the state or archipelago. The archipelago is physiographically and ethnologically part of the Polynesian subregion of Oceania, Hawaii has over a million permanent residents, along with many visitors and U. S. military personnel. Its capital is Honolulu on the island of Oʻahu, Hawaii is the 8th-smallest and the 11th-least populous, but the 13th-most densely populated of the fifty U. S. states. It is the state with an Asian plurality. The states coastline is about 750 miles long, the fourth longest in the U. S. after the coastlines of Alaska, Florida, the state of Hawaii derives its name from the name of its largest island, Hawaiʻi. A common Hawaiian explanation of the name of Hawaiʻi is that was named for Hawaiʻiloa and he is said to have discovered the islands when they were first settled. The Hawaiian language word Hawaiʻi is very similar to Proto-Polynesian *Sawaiki, cognates of Hawaiʻi are found in other Polynesian languages, including Māori, Rarotongan and Samoan. According to linguists Pukui and Elbert, lsewhere in Polynesia, Hawaiʻi or a cognate is the name of the underworld or of the home, but in Hawaii. A somewhat divisive political issue arose in 1978 when the Constitution of the State of Hawaii added Hawaiian as an official state language. The title of the constitution is The Constitution of the State of Hawaii. Article XV, Section 1 of the Constitution uses The State of Hawaii, diacritics were not used because the document, drafted in 1949, predates the use of the okina and the kahakō in modern Hawaiian orthography. The exact spelling of the name in the Hawaiian language is Hawaiʻi. In the Hawaii Admission Act that granted Hawaiian statehood, the government recognized Hawaii as the official state name. Official government publications, department and office titles, and the Seal of Hawaii use the spelling with no symbols for glottal stops or vowel length
22.
1933 Sanriku earthquake
–
The 1933 Sanriku earthquake occurred on the Sanriku coast of the Tōhoku region of Honshū, Japan on March 2. The earthquake had a moment magnitude of 8.4 and the tsunami caused widespread damage. The epicenter of the 1933 Sanriku earthquake was located offshore,290 kilometres east of the city of Kamaishi, the initial shock occurred at 0231 AM local time on March 3,1933. The earthquake measured 8.4 on the moment magnitude scale and was in approximately the location as the 1896 Meiji-Sanriku earthquake. The epicenter occurred far enough away from the town that the earthquake itself did little damage to buildings, approximately three hours after the main shock was a magnitude 6.8 aftershock, followed by 76 more aftershocks over a period of six months. This earthquake was an earthquake in the Pacific Plate. The focal mechanism of this showed that it was a normal faulting earthquake. Although the earthquake did little damage, the tsunami, which was recorded to reach the height of 28. The tsunami was recorded in Hawaii with a height of 9.5 feet. The death toll came to 1522 people confirmed dead,1542 missing, hardest hit was the town of Tarō, Iwate, with 98% of its houses destroyed and 42% of its population killed. List of earthquakes in 1933 List of earthquakes in Japan Seismicity of the Sanriku coast Historic video footage of devastation following 1933 Sanriku Earthquake
23.
Fukushima Daiichi nuclear disaster
–
The Fukushima Daiichi nuclear disaster was an energy accident at the Fukushima I Nuclear Power Plant in Fukushima, initiated primarily by the tsunami following the Tōhoku earthquake on 11 March 2011. Immediately after the earthquake, the reactors automatically shut down their sustained fission reactions. However, the disabled the emergency generators that would have provided power to control. The insufficient cooling led to three nuclear meltdowns, hydrogen-air chemical explosions, and the release of material in Units 1,2 and 3 from 12 March to 15 March. Loss of cooling also caused the pool for storing spent fuel from Reactor 4 to overheat on 15 March due to the heat from the fuel rods. On 12 October 2012, TEPCO admitted for the first time that it had failed to take measures for fear of inviting lawsuits or protests against its nuclear plants. However, an estimated 1,600 deaths are believed to have occurred due to the resultant evacuation conditions, There are no clear plans for decommissioning the plant, but the plant management estimate is 30 or 40 years. Radiation levels of about 650 sieverts per hour have been detected in the containment vessel of reactor No.2, the Fukushima I Nuclear Power Plant comprised six separate boiling water reactors originally designed by General Electric and maintained by the Tokyo Electric Power Company. At the time of the Tōhoku earthquake on 11 March 2011, however, their spent fuel pools still required cooling. As the reactors were unable to power to run their own coolant pumps, emergency diesel generators came online, as designed, to power electronics. These operated nominally until the destroyed the generators for reactors 1–5. The largest tsunami wave was 13 meters high and hit 50 minutes after the earthquake, overwhelming the plants seawall. The moment of impact was recorded by a camera, water quickly flooded the low-lying rooms in which the emergency generators were housed. The flooded diesel generators failed soon afterwards, resulting in a loss of power to the coolant water pumps. The fuel rods would become hot enough to melt during the decay time period if an adequate heat sink was not available. After the secondary emergency pumps ran out, one day after the tsunami,12 March, the pumps stopped. The insufficient cooling led to meltdowns in reactors 1,2, and 3. It is estimated that the hot zirconium fuel cladding-water reaction in reactors 1–3 produced 800 to 1000 kilograms of hydrogen gas each
24.
International Standard Book Number
–
The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
25.
Plate tectonics
–
The theoretical model builds on the concept of continental drift developed during the first few decades of the 20th century. The geoscientific community accepted plate-tectonic theory after seafloor spreading was validated in the late 1950s, the lithosphere, which is the rigid outermost shell of a planet, is broken up into tectonic plates. The Earths lithosphere is composed of seven or eight major plates, where the plates meet, their relative motion determines the type of boundary, convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries. The relative movement of the plates typically ranges from zero to 100 mm annually, tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle, the material lost is balanced by the formation of new crust along divergent margins by seafloor spreading. In this way, the surface of the lithosphere remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle, earlier theories, since disproven, proposed gradual shrinking or gradual expansion of the globe. Tectonic plates are able to move because the Earths lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the ridge and drag, with downward suction. Another explanation lies in the different forces generated by forces of the Sun. The relative importance of each of these factors and their relationship to other is unclear. The outer layers of the Earth are divided into the lithosphere and asthenosphere and this is based on differences in mechanical properties and in the method for the transfer of heat. Mechanically, the lithosphere is cooler and more rigid, while the asthenosphere is hotter, in terms of heat transfer, the lithosphere loses heat by conduction, whereas the asthenosphere also transfers heat by convection and has a nearly adiabatic temperature gradient. The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, Plate motions range up to a typical 10–40 mm/year, to about 160 mm/year. The driving mechanism behind this movement is described below, tectonic lithosphere plates consist of lithospheric mantle overlain by either or both of two types of crustal material, oceanic crust and continental crust. Average oceanic lithosphere is typically 100 km thick, its thickness is a function of its age, as passes, it conductively cools
26.
Okhotsk Plate
–
The Okhotsk Plate is a minor tectonic plate covering the Sea of Okhotsk, the Kamchatka Peninsula, Sakhalin Island and Tōhoku and Hokkaidō in Japan. It was formerly considered a part of the North American Plate, the boundary is a left-lateral moving transform fault, the Ulakhan Fault. The earthquake devastated Neftegorsk, and the town was not rebuilt after the earthquake, other notable intraplate earthquakes such as the 1983 Sea of Japan earthquake and the 1993 Hokkaidō earthquake triggered tsunamis in the Sea of Japan. The boundary between Okhotsk Plate and Pacific Plate is a zone, where Pacific Plate subducts beneath the Okhotsk Plate. Many strong megathrust earthquakes occurred here, some of them among the largest on world record, GPS measurements and other studies show that the Okhotsk Plate is slowly rotating in a clockwise direction. Models indicate that it rotates 0.2 deg/Myr about a pole located north of Sakhalin, Okhotsk Plate Modeling Joint US-Russia Workshop on the Plate Tectonic Evolution of Northeast Russia, Dec.2004
27.
1771 Great Yaeyama Tsunami
–
According to records,8,439 persons were killed on Ishigaki Island and 2,548 on Miyako Island. According to the Japanese government publication Rika-Nenpyō or Chronological Scientific Tables, according to the Mamoru Nakamura Laboratory, University of the Ryukyus, the earthquake was due to the activity of the fault east of Ishigaki and it is estimated that the magnitude was 7.5. Further simulation led to the activity of faults in the Ryukyu oceanic trench, also, there is a hypothesis that claims the magnitude was 8.5. This trench lies between the Philippine Sea Plate and the Eurasian Plate and it is considered that the earthquake registered an intensity of 4 in Yaeyama, and the damage by the earthquake was not as serious as the tsunami. The dead and missing amounted to 12,000 people, and more than 2,000 houses were destroyed on Ishigaki, agriculture was severely damaged because of sea water invasion and the population decreased to about one third of what it was before the earthquake. On Ishigaki island, the wave was 40 to 80 meters high, there are many huge rocks believed to have been left by the earthquake. There was a legend that an islet disappeared, but this has never been verified
28.
1792 Unzen earthquake and tsunami
–
The 1792 Unzen earthquake and tsunami resulted from the volcanic activities of Mount Unzen on 21 May. This caused the collapse of the flank of the Mayuyama dome in front of Mount Unzen, resulting in a tremendous tsunami. It was also called, Shimabara erupted, Higo affected, since people were killed by this tsunami in Higo. Towards the end of 1791, a series of earthquakes occurred on the flank of Mount Unzen which gradually moved towards Fugen-dake. In February 1792, Fugen-dake started to erupt, triggering a lava flow which continued for two months, meanwhile, the earthquakes continued, shifting nearer to the city of Shimabara. It is not known to this day whether the collapse occurred as a result of an eruption of the dome or as a result of the earthquakes, the tsunami struck Higo Province on the other side of Ariake Bay before bouncing back and hitting Shimabara again. The waves reached a height of 33–66 ft, classing this tsunami as a small megatsunami, at the Osaki-bana point Futsu town, the waves locally grew to a height of 187 ft due to the effect of sea bottom topography. As of July,1991, the monuments have been found. Lake Shirachi is a pond in Shimabara city, Nagasaki Prefecture which was created after the landslide at Mayuyama created by the inpouring of underground water. Its size was first 1 km and 300m 400m, but the production of a water exit river made it smaller, as a result of the destruction, Tsukumojima or 99 islets or rocks were distributed near Shimabara city. In the same Nagasaki Prefecture, there are 99 islands or Kujūkushima distributed from Sasebo city to Hirado city and these islands are different from Tsukumojima. 1771 Great Yaeyama Tsunami List of earthquakes in Japan List of historical earthquakes
