Myoko Volcano Relief Map, SRTM-1 (closeup)

is an

active Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * ''Active'' (ship), several commercial ships by that name * HMS ''Active'', the name of various ships of the British Royal ...

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and p ...

Honshu , 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 ...

, Japan. It is situated at the southwest of Myōkō city,

Niigata Prefecture is a prefecture in the Chūbu region of Honshu of Japan. Niigata Prefecture has a population of 2,227,496 (1 July 2019) and is the fifth-largest prefecture of Japan by geographic area at . Niigata Prefecture borders Toyama Prefecture and N ...

, and a part of Jōshin'etsu-kōgen National Park. Mount Myōkō is listed as one of

100 Famous Japanese Mountains is a book written in 1964 by mountaineer and author Kyūya Fukada.Hyakumeizan, Hiking Japan!
. Japa ...

, and together with , it is well known as the "famous mountain" of Niigata Prefecture.

Name

is another name given to this mountain. Being close to the border with

Nagano Prefecture is a landlocked prefecture of Japan located in the Chūbu region of Honshū. Nagano Prefecture has a population of 2,052,493 () and has a geographic area of . Nagano Prefecture borders Niigata Prefecture to the north, Gunma Prefecture to the n ...

, it is linked to those on the Nagano side as one of the . The mountain was originally named but was later changed to . This can be also written as 妙高山, in order to make use of two "lucky" characters.

Geology and geography

Mount Myōkō was formed beginning about 300,000 years ago, in a series of eruptions producing a broad spectrum of lava types including

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomina ...

, and

dacite Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained ( aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhy ...

. Its maximum height is estimated to have been between and , but it presently reaches only . Around 19,000 years ago, the top was blown off in a major

eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are of ...

, forming a wide

caldera 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 ...

. About 6,000 years ago, the central crater developed and assumed its present shape. A

lava dome In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruption ...

forms the volcano's present summit. The most recent eruptions about 4,300 years ago produced

pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...

s down the eastern flanks. Present activity is solfataric from

fumarole A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcan ...

s near the lava dome where

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

was once mined. There are

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 ...

and

ski resort A ski resort is a resort developed for skiing, snowboarding, and other winter sports. In Europe, most ski resorts are towns or villages in or adjacent to a ski area – a mountainous area with pistes (ski trails) and a ski lift system. In N ...

s at the foot of the mountain, including Akakura, Suginohara and Ikenotaira.

Related facts

The

heavy cruiser The heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in caliber, whose design parameters were dictated by the Washington Naval ...

'' Myōkō'' of the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

and an

Aegis The aegis ( ; grc, αἰγίς ''aigís''), as stated in the ''Iliad'', is a device carried by Athena and Zeus, variously interpreted as an animal skin or a shield and sometimes featuring the head of a Gorgon. There may be a connection with a d ...

destroyer of the

Japan Maritime Self-Defense Force , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy (IJN) ...

are named after this mountain. The JR East train service '' Myōkō'' is also named after the mountain. The mountain appears invariably in school songs of elementary and middle schools in the Jōetsu Region. In 1990 the Nippon Jamboree, a camping festival, was held on the during which the participants climbed the mountain.

References

External links

Myokosan
- Japan Meteorological Agency * - Japan Meteorological Agency

- Geological Survey of Japan * {{DEFAULTSORT:Myoko, Mount Mountains of Niigata Prefecture Stratovolcanoes of Japan Volcanoes of Honshū Volcanoes of Niigata Prefecture Myōkō, Niigata Pleistocene stratovolcanoes Holocene stratovolcanoes

Name

Geology and geography

Related facts

See also

References

External links