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Naruko (volcano)
is a stratovolcano located in Ōsaki, Miyagi Prefecture, Japan. The volcano consists of a 7 km wide caldera with several lava domes. The summit of the 470 m high Mt. Kurumigatake is one of the four lava domes located in the center of the caldera. The volcano is well known because of its relationship to the Naruko Hot Springs Villages. However, its lack of well-defined features makes it difficult to recognize for a casual observer. The Japan Metrological Agency considers Naruko to be an active volcano. The Naruko volcano was formed through two pyroclastic flows, which occurred 73,000 and 45,000 years ago. The first lava domes were formed approximately 20,000 years ago. The rocks produced by the pyroclastic flows and lava domes vary in composition, but are generally dacitic. Subsequent volcanic activity continued to create more lava domes, while also resulting in explosive eruptions that destroyed such domes. Tephra created by an explosive eruption approximately 18, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honshū
, historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separates the Sea of Japan, which lies to its north and west, from the North Pacific Ocean to the south and east. 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 104 million , constituting 81.3% of the entire population of Japan, and is mostly concentrated in the coastal areas and plains. Approximately 30% of the total population resides in the Greater Tokyo Area on the Kantō Plain. As the historical center of Japanese cultural and political power, the island includes several past Japanese capitals, including Kyōto, Nara and Kamakura. Much of the island's southern shore forms part of the Taiheiyō Belt, a megalopolis that spans several of the Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoku Nihon Kōki
is an officially commissioned Japanese history text. Completed in 869, it is the fourth volume in the Six National Histories. It covers the years 833–850. Background Following the earlier national history ''Nihon Kōki'' (840), in 855 Emperor Montoku ordered the compilation of the years since then. Primarily edited by Fujiwara no Yoshifusa and Haruzumi no Yoshitsuna, the text was completed in 869. Contents Written in Kanbun-style and contained within 20 volumes, the contents covered 18 years spanning 833 and 850. As opposed to the previous national histories, it is the first to cover a single reign, that of Emperor Ninmyō setting the model for future national histories. See also * ''Ruijū Kokushi'', a categorized and chronological history text of the ''Six National Histories''; valuable resource in recreating lost contents of the ''Shoku Nihon Kōki'' References * * External linksText of the ''Shoku Nihon Kōki''(Japanese) *Manuscript scans, Waseda University Library ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Miyagi Prefecture
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Crater Lakes
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Volcanoes
An active volcano is a volcano which is either erupting or is likely to erupt in the future. An active volcano which is not currently erupting is known as a dormant volcano. Overview Tlocene Epoch. Most volcanoes are situated on the Pacific Ring of Fire. An estimated 500 million people live near active volcanoes. ''Historical time'' (or recorded history) is another timeframe for ''active''. However, the span of recorded history differs from region to region. In China and the Mediterranean, it reaches back nearly 3,000 years, but in the Pacific Northwest of the United States and Canada, it reaches back less than 300 years, and in Hawaii and New Zealand it is only around 200 years. The incomplete ''Catalogue of the Active Volcanoes of the World'', published in parts between 1951 and 1975 by the International Association of Volcanology, uses this definition, by which there are more than 500 active volcanoes. , the Smithsonian Global Volcanism Program recognizes 560 volcanoes with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction Volcanoes
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calderas Of Honshū
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', meaning "coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Honshū
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In Japan
This is a list of active and extinct volcanoes in Japan. An Orange background indicates a volcano considered active by the Japan Meteorological Agency. Hokkaido Honshū Izu Islands Ogasawara Archipelago The Ogasawara Archipelago include the Bonin Islands and Volcano Islands. Kyūshū Ryūkyū Islands See also * Notes and references Notes References External links Quaternary Volcanoes of Japan- Geological Survey of Japan - Geological Survey of Japan * ttp://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/souran_eng/souran.htm The National Catalogue of the Active Volcanoes in Japan- Japan Meteorological Agency 日本の主な山岳標高 (Elevation of Principal Mountains in Japan)- Geospatial Information Authority of Japan {{Asia topic, List of volcanoes in Japan Lists of coordinates Volcanoes A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phreatic Eruption
A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from ) causes near-instantaneous evaporation of water to steam, resulting in an explosion of steam, water, ash, rock, and volcanic bombs. At Mount St. Helens in Washington state, hundreds of steam explosions preceded the 1980 Plinian eruption of the volcano. A less intense geothermal event may result in a mud volcano. Phreatic eruptions typically include steam and rock fragments; the inclusion of liquid lava is unusual. The temperature of the fragments can range from cold to incandescent. If molten magma is included, volcanologists classify the event as a phreatomagmatic eruption. These eruptions occasionally create broad, low-relief craters called '' maars''. Phreatic explosions can be accompanied by carbon dioxide or hydrogen sulfide gas-emissions. Carbon dioxide c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onsen
In Japan, are the country's hot springs and the bathing facilities and traditional inns around them. As a volcanically active country, Japan has many onsens scattered throughout all of its major islands. There are approximately 25,000 hot spring sources throughout Japan that provide hot mineral water to about 3,000 genuine onsen establishments. Onsens come in many types and shapes, including and . Baths may be either publicly run by a municipality or privately, often as part of a hotel, ''ryokan'', or . The presence of an onsen is often indicated on signs and maps by the symbol ♨ or the kanji (''yu'', meaning "hot water"). Sometimes the simpler hiragana character ゆ (''yu''), understandable to younger children, is used. Traditionally, onsens were located outdoors, although many inns have now built indoor bathing facilities as well. Nowadays, as most households have their own bath, the number of traditional public baths has decreased, but the number of sightseeing ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they remain as tephra unless hot enough to fuse into pyroclastic rock or tuff. Tephrochronology is a geochronological technique that uses discrete layers of tephra—volcanic ash from a single eruption—to create a chronological framework in which paleoenvironmental or archaeological records can be placed. When a volcano explodes, it releases a variety of tephra including ash, cinders, and blocks. These layers settle on the land and, over time, sedimentation occurs incorporating these tephra layers into the geologic record. Often, when a volcano explodes, biological organisms are killed and their remains are buried within the tephra layer. These fossils are later dated by scientists to determine the age of the fossil and its place within the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
