The Musashino Plateau ( 武蔵野台地 , Musashino daichi ) , also translated from Japanese as Musashino Platform and also named Musashino Region , is a large tableland that sits between the Arakawa and Tama rivers in the Kantō region of Honshu , Japan . The plateau consists of an alluvial fan formed by the ancient Tama River, covered by a layer of loam formed from volcanic ash .
31-641: The plateau is part of the Kantō Plain . It sits northwest of Tokyo Bay , in the southwest of the plain. Its northern section is in southern Saitama Prefecture . Much of Tokyo , between the Tama River to the south and the Arakawa River to the north, is built on the plateau. The Tama River carved the Okutama Mountains and deposited a large alluvial fan that spread out from Ōme . The fan is
62-576: Is also another mountain called Asama (朝熊山, Asama-yama ) of only 555 meters in Mie Prefecture . The geologic features of this active volcano are closely monitored with seismographs and strategically positioned video cameras. Scientists have noted a range of textural variety in the ash which has been deposited in the region during the serial eruptions since the Tennin eruption of 1108. The eruption of Mount Asama in 1108 ( Tennin 1 ) has been
93-489: Is an active complex volcano in central Honshū , the main island of Japan . The volcano is the most active on Honshū. The Japan Meteorological Agency classifies Mount Asama as rank A. It stands 2,568 metres (8,425 ft) above sea level on the border of Gunma and Nagano prefectures . It is included in 100 Famous Japanese Mountains . Mount Asama sits at the conjunction of the Izu–Bonin–Mariana Arc and
124-459: Is recorded several times during the winter. Throughout the year, the entire Kanto Plain, especially the inland areas, are easily affected by radiative cooling due to clear skies and north winds, so the minimum temperature before sunrise can drop to about 5 degrees below zero in winter. Even on days when the temperature drops at dawn, the daytime temperature rises to about 7 to 10 degrees Celsius on sunny days, and on days with strong dry north winds,
155-629: Is the Tachikawa terrace, and the terrace one step higher than that (high surface) is the Musashino terrace. The other is in the north and is thought to be a remnant of the former Tama River channel. This article about a regional geological feature is a stub . You can help Misplaced Pages by expanding it . Kant%C5%8D Plain 36°00′N 140°00′E / 36.000°N 140.000°E / 36.000; 140.000 The Kantō Plain ( Japanese : 関東平野 , Hepburn : Kantō heiya ) , in
186-552: Is the name of a lava flow on the northern slope of Mount Asama. The lava flow that erupted in 1783 Tenmei eruption was solidified. Now, it is known as a tourist destination. The Asama Volcano Museum ( 浅間火山博物館 ), 4 km (2.5 mi) from the crater of the Mount Asama, open from 1993 to 2020, explained volcanoes. The museum was in Naganohara-machi , Agatsuma-gun , Gunma Prefecture . As of early 2009, it
217-644: The Kantō region of central Honshu , is the largest plain in Japan . Its 17,000 km covers more than half of the region extending over Tokyo , Saitama Prefecture , Kanagawa Prefecture , Chiba Prefecture , Gunma Prefecture , Tochigi Prefecture , and Ibaraki Prefecture . The northern limit borders on the Abukuma Highlands , Yamizo Mountain Range , Ashio Mountain Range, and a volcanic field associated with
248-756: The Northeastern Japan Arc . The mountain is built up from non-alkali mafic and pyroclastic volcanic rocks dating from the Late Pleistocene to the Holocene . The main rock types are andesite and dacite . Scientists from the University of Tokyo and Nagoya University completed their first successful imaging experiment of the interior of the volcano in April 2007. By detecting sub-atomic particles called muons as they passed through
279-588: The Kanto basin-forming movement, which has continued since the Neogene period . This movement is what caused sedimentation in the center of the present-day Kanto Plain and uplift of the surrounding mountains. As a result, sediment from the surrounding mountains was deposited very thickly (the Tertiary layer reaches as high as 3,000 meters) and further uplifted to form many hills and plateaus. Large tectonic lines such as
310-574: The Kantō Plain stand on Tertiary strata and rise higher than surrounding plateaus, exemplified by the Sayama Hills and Tama Hills , typically, undulating between 100 and 200 m above sea level. Hills located at the western edge of the Kantō Plain, the Hiki Hills, Koma Hills, Kusahana Hills, and Kaji Hills, also reach approximately 200 m (660 ft) above sea level. The overall tilt of
341-726: The Nasu Volcanic Belt. The western coincides with the Kantō Mountain Range , and the southern edge is defined by the Bōsō Peninsula , the Miura Hills , Tokyo Bay , and Sagami Bay . The Kashima Sea and Kujūkuri Beach define the eastern end of the plain. Most of its rivers originate in the northern or western mountain ranges and flow east or southeast into the Pacific Ocean , Tokyo Bay , or Sagami Bay . In
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#1732765491797372-465: The alluvial lowland of the Kantō Plain. A collection of plateaus constitute a large part of the plain. Among them are the Ōmiya, Musashino , Sagamino , Jōsō , and Shimōsa Plateaus. These large plateaus are divided into smaller ones by shallow river valleys. A common feature of the plateaus is that their surfaces are covered with a thick layer of loam of volcanic origin. Volcanic ash from surrounding volcanoes, Mounts Asama , Haruna , and Akagi to
403-555: The base layer of the Musashino Plateau, and is covered by the Kantō Loam Formation, which is 5 to 15 meters thick. The loam is primarily andesite or basaltic sandy mud formed from volcanic ash that the wind carried west from Mount Fuji . Two types of developed fluvial terraces (river terraces) are found on the plateau. One is formed by the flow of the Tama River on the south side. The lowest terrace (low surface)
434-736: The central part of the plain is the Tone River ; in the northern part the Watarase River , Kinu River , Kokai River, Naka River , and Kuji River ; and in the southern part the Arakawa River , Tama River , and Sagami River . Of these, the Tone River encompasses a large area of floodplain, for its drainage area of 16,840 km (6,500 sq mi) is the largest in Japan. The drainage areas covered by these rivers account for
465-433: The cone. The climactic eruption began on 4 August and lasted for 15 hours, and contained pumice falls and pyroclastic flows. The complex features of this eruption are explained by rapid deposits of coarse pyroclastic ash near the vent and the subsequent flows of lava; and these events which were accompanied by a high eruption plume which generated further injections of pumice into the air. Explosive eruptions occurred at
496-544: The eastern margin of the Fossa Magna and the Median Tectonic Line are thought to exist in the central part of the plain, but this thick accumulation of soft sedimentary layers makes it difficult to find active faults that can cause earthquakes (faults exist in the base 3000m below the sedimentary layers). In addition, natural sediments such as sediment carried by rivers have been used to create land, and
527-491: The late Heian Period (794–1185) the diary of the court noble Fujiwara no Munetada reported that Mount Asama erupted on 29 August 1108. He wrote that a local report described rice paddies and fields could not be farmed due to being covered by a thick layer of ash. Mount Asama erupted in 1783 ( Tenmei 3 ), causing widespread damage. The three-month-long plinian eruption that began on 9 May 1783, produced andesitic pumice falls, pyroclastic flows, lava flows, and enlarged
558-1090: The mountain. The eruptions of Mount Asama mark the span of Japan's recorded history, including: 2019, 2009 , 2008 , 2004 , 2003, 1995 , 1990, 1983 , 1982 , 1973, 1965, 1961, 1958–59, 1953–55, 1952, 1952, 1950–51, 1949, 1947, 1946, 1944–45, 1938–42, 1935–37, 1934, 1934, 1933, 1931–32, 1930, 1929, 1929, 1927–28, 1924, 1922, 1920–21, 1919, 1918?, 1917, 1916, 1915, 1914, 1909–14, 1908, 1908, 1907, 1907, 1906, 1905?, 1904, 1903, 1902, 1902, 1900–01, 1899, 1899, 1894, 1889, 1879, 1878?, 1875, 1869, 1815, 1803, 1803, 1783 , 1779?, 1777, 1776, 1769, 1762, 1755, 1754, 1733, 1732, 1731, 1729, 1729, 1728, 1723, 1723, 1722, 1721, 1720, 1719, 1718, 1717, 1711, 1710, 1708–09, 1706, 1704, 1703, 1669, 1661, 1661, 1660, 1659, 1658, 1657, 1656, 1655, 1653, 1652, 1651, 1650?, 1649, 1648, 1648, 1647, 1645, 1644, 1609, 1605, 1604, 1600, 1598, 1597, 1596, 1596, 1595?, 1591, 1590, 1532, 1528, 1527, 1518, 1427?, 1281, 1108 , 887, 685. Note: The dates of eruptions featured in this article appear in bold italics. Onioshidashi ( Japanese : 鬼押出し ) "expelling demons"
589-501: The north and Mounts Hakone and Fuji to the southwest, are thought to have been deposited on these plateaus. Among the plateaus, the Musashino Plateau has the largest stretch of land, extending from the western edge of Ōme to the eastern edge of Yamanote , which borders the alluvial plains of the Arakawa and Sumida Rivers. Its elevation gradually declines from west to east, measuring 190 m at Ōme and 20 m at Yamanote. Hills in
620-543: The northern part. Due to the influence of the Black Current (warm current) flowing along the coast, the climate is mild, especially in the southern part. In summer, rainfall is heavy due to the rainy season front caused by monsoon, and typhoons are often seen. Thunderclouds that form in the northern to western mountains areas before noon reach the plains in the early afternoon, often resulting in evening showers (thunderstorms). In years when Okhotsk anticyclone prevails,
651-410: The plateaus and hills is noteworthy. In general, the whole area is slightly bent and forming a basin centered in the Tone River and Tokyo Bay. The ongoing process of tectonic extension continues as the plain's central region gradually sinks. The Kantō Plain witnessed its greatest devastation from an earthquake on 1 September 1923 , with a death toll calculated of 142,807. Kanto Plain was formed by
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#1732765491797682-578: The sensory temperature is lower than the actual temperature. The lowest temperatures in central Tokyo are higher than those in surrounding areas due to the heat island effect. Kumagaya tends to get hotter because of being inland, foehn phenomenon, which occurs when the wind in the sky above blows down after crossing the mountains on the north and west sides of the Kanto Plain, and the sea breeze that warms up while passing through central Tokyo. Mount Asama Mount Asama ( 浅間山 , Asama-yama )
713-609: The subject of studies by modern science. Records suggest that the magnitude of this plinian eruption was twice as large as that of the Tenmei catastrophe in 1783 . A Swiss research team found Mount Asama's volcanic eruption could have contributed to extreme weather that caused severe famine, torrential rain and consecutive cold summers in Europe. They studied ice cores in Greenland which had increased sulfate deposition in 1108 CE. In
744-464: The summit and caused many fires. The eruption sent ash and rock as far away as 200 km (120 mi). Three small ash eruptions occurred at Asama volcano in August 2008. This was the first activity at the volcano since 2004. Mount Asama erupted in early February 2009, sending ash to a height of 2 km (6,600 ft), and throwing rocks up to 1 km (0.62 mi) from the crater. Ash fall
775-581: The summit of Asama volcano on 26 April. Fine ash fell in Tokyo, 130 km (80 mi) to the SE, for the first time in 23 years. An explosive eruption occurred on 8 April. Incandescent tephra was ejected, and ash fell 250 km (160 mi) from the volcano. In April 1995, more than 1000 earthquakes were detected at the volcanic mountain. A single vulcanian eruption occurred at Asama volcano at 11:02 UT on 1 September 2004. Incandescent blocks were ejected from
806-460: The terrain was almost the same as it is today in the Late Jomon to Early Yayoi Period (more than 3,000 years ago). The climate of the Kanto Plain is temperate, with a Pacific Ocean side climate. Winters are cold and summers are hot. The further inland, the greater the temperature difference between summer and winter, and within a day. There are relatively many hours of sunshine, especially in
837-414: The town of Naganohara. Additionally, the building was ageing, and maintenance threatened to cost hundreds of millions of yen. A nearby building, Asama memorial hall ( 浅間記念館 ) exhibited motorbikes; the plan in summer 2020 was to move these to a municipally owned tourist facility, Asama pasture ( 浅間牧場 ), and to move some of the exhibits of the volcano museum to the memorial hall. Mount Asama served as
868-491: The volcano after arriving from space, the scientists were able gradually to build up a picture of the interior, creating images of cavities through which lava was passing deep inside the volcano. A University of Tokyo volcano observatory is located on the mountain's east slope. Volcanic gas emissions from this volcano are measured by a Multi-Component Gas Analyzer System , which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity . There
899-910: The winds from this anticyclone become northeasterly winds, and temperatures do not rise due to the cool air brought in by the Yamase, resulting in a cold summer. In winter, the monsoon from the Sea of Japan is blocked by the Mikuni Mountains, and the moisture falls as snow along the mountains to the north, and the monsoon that has lost its moisture blows through the Kanto Plain as a strong gale carrying dry air (such as Akagi Orosi in Gunma Prefecture , Tsukuba Orosi in Ibaraki Prefecuture and Futaara Orosi). Snowfall has been decreasing year by year, but snow accumulation of around 10–20 cm
930-413: Was open from April until November. Visitor numbers peaked at 265,000 in 1994; however, seismic activity at nearby Mount Asama was one reason for frequent closures. The closures were a factor in the drop in visitors: this gradually fell to 23,000. In the later years of the museum, most of the visitors were on school excursions. The museum was running a deficit of about 17 million yen per year, paid for by
961-554: Was reported in Tokyo, 145 km (90 mi) southeast of the volcano crater. On 16 February there were 13 recorded volcanic earthquakes and an eruption emitting smoke and ash in a cloud 400 m (1,300 ft) high. Mount Asama continued to have small eruptions, tremors and earthquakes in February and remained on level-3 alert, with a danger zone within 4 km (2.5 mi) of the crater. A small eruption occurred on August 7th, 2019, with smoke reaching about 1,800 meters above