Mount Fuji
, or Fugaku, located on the island of Honshū, is the highest mountain in Japan, with a summit elevation of . It is the second-highest volcano located on an island in Asia (after Mount Kerinci on the island of Sumatra), and seventh-highest p ...
is the tallest
volcano
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 ...
in
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, and also the highest peak. The latest eruption of Mount Fuji was in 1707, and it was triggered by an
earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
.
The mountain as it appears now is the "New Fuji volcano", which began to erupt about 10,000 years ago. Under the "New Fuji volcano" lies the "Old Fuji volcano", which was active between 100,000 years ago and 10,000 years ago, and the "Komitake volcano", which became
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 ...
700,000 years ago.
Prehistory
Komitake and Old Fuji
There has been volcanic activity in the vicinity of Mount Fuji for several million years. The earliest geologically known volcano was that became active 700,000 years ago. Another volcano to the south-east of Mount Fuji—known as —was also highly active throughout the period. The peak of Komitake is about above sea-level on the north face of Mount Fuji (at the fifth station).
Komitake entered another period of activity around 100,000 years ago. This created a new volcano known as that reached a height of . It created many explosive eruptions that threw out large amounts of
scoria
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''G ...
,
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...
and
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
.
New Fuji
Following the Old Fuji period, there were about 4,000 years of inactivity, ending at around 5,000 years ago, when Mount Fuji became active again; this period is known as , and continues to the present day. Eruptions of New Fuji exhibit phenomena such as
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
flows,
magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
,
scoria
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''G ...
,
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...
, collapses and side eruptions, leading it to be called "a department store of eruptions". Ash from New Fuji is often black, and eruptions are new in terms of geological layers. Valuable data on the activity of Mount Fuji is recorded in Japanese historical documents dating from the 8th century onwards. It exhibits a range of representative eruptions.
The Gotemba mud flow
About 2,300 years ago the east face of the volcano collapsed and
lahars
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley.
Lahars are extremel ...
flowed down to the
Gotemba
is a city on the southeastern flank of Mount Fuji in Shizuoka Prefecture, Japan. , the city had an estimated population of 88,370 in 36,096 households, and a population density of 450 persons per km². The total area of the city is .
Geography ...
area as far as the Ashigara plain in the east and the Suruga bay across Mishima city in the south. This incident is now called the . Liquid mud piled up over an area as wide as the city area of Mishima.
Jōgan eruption
In 864 (the 6th year of the ''
Jōgan
was a after ''Ten'an'' and before '' Gangyō.'' This period spanned the years from April 859 through April 878. The two reigning emperors were and .
Change of era
* February 7, 859 : The new era name was created to mark an event or series of ...
'' era) there was an eruption on the north-east side of Mount Fuji, which produced a great amount of lava.
* 864 (''Jōgan 6, 5th month''): Mount Fuji erupted for 10 days, and it ejected from its summit an immense quantity of cinders and ash which fell back to earth as far away as the ocean at lake. Many people perished and many homes were destroyed. The volcanic eruption began on the side of Fuji-san closest to Mount Asama, throwing cinders and ash as far away as
Kai province. Some of the lava filled up a large lake which existed at the time, dividing it into two lakes, and . This is known as the , and at present is covered by the dense
Aokigahara
Aokigahara (), also known as the , is a forest on the northwestern flank of Mount Fuji on the island of Honshu in Japan, thriving on of Igneous rock, hardened lava laid down by the last major Historic eruptions of Mount Fuji, eruption of Moun ...
forest.
Hōei eruption
The latest eruption, in 1707 (the 4th year of the ''
Hōei
was a after Genroku and before Shōtoku''.'' This period spanned the years from March 1704 through April 1711. The reigning emperors were and .
Change of era
* 1704 : In reaction to the Great Genroku earthquake in Genroku 16, the era name w ...
'' era), was known as the
great ''Hōei'' eruption. It followed several weeks after the
Great ''Hōei'' earthquake, an 8.7 on the Richter scale. The earthquake severely damaged the city of Osaka, but more than that, it created enough seismic activity to compress the magma chamber 20 km deep in the inactive Mt. Fuji. Due to the compression of the magma chamber, basaltic lava rose from the bottom to the higher dacitic magma chamber at 8 km deep. The mixing of the two different types of magma caused a
Plinian eruption to occur. Previous to the Hoei, another earthquake named
Genroku
was a after Jōkyō and before Hōei. The Genroku period spanned the years from the ninth month of 1688 to the third month of 1704. The reigning emperor was .Titsingh, Isaac. (1834). ''Annales des empereurs du japon'', p. 415.
The period was ...
had struck Japan in 1703. The earthquake affected both Kanagawa and Shizuoka prefectures, and was measured as an 8.2 on the Richter Scale. The Genroku earthquake had a similar effect on Mt. Fuji as Hoei but with less severity. It clamped the dike of the mountain at 8 km to the surface (where the dacitic magma resides), as well as the basaltic chamber at 20 km deep. Many articles found a correlation between the two earthquakes, arriving at the conclusion that without either earthquake the Hoei eruption would not have happened.
* November 11, 1707 (''Hōei 4, 14th day of the 10th month''): The city of Osaka suffers tremendously because of a very violent earthquake.
* December 16, 1707 (''Hōei 4, 23rd day of the 11th month''): An eruption of
Mount Fuji
, or Fugaku, located on the island of Honshū, is the highest mountain in Japan, with a summit elevation of . It is the second-highest volcano located on an island in Asia (after Mount Kerinci on the island of Sumatra), and seventh-highest p ...
; the cinders and ash fell in
Izu Izu may refer to:
Places
*Izu Province, a part of modern-day Shizuoka prefecture in Japan
**Izu, Shizuoka, a city in Shizuoka prefecture
**Izu Peninsula, near Tokyo
**Izu Islands, located off the Izu Peninsula
People with the surname
*, Japane ...
,
Kai,
Sagami Sagami may refer to:
* Sagami, an 11th-century ''waka'' poet
*Sagami Province, an old province in Japan
*Sagami River, a river in Kanagawa and Yamanashi
*Sagami Bay, a bay south of Kanagawa Prefecture in Honshū
*Sagami Line, a railway roughly along ...
, and
Musashi. This eruption was remarkable, as it spread a vast amount of
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...
and
scoria
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''G ...
over a region as far as
Edo (now Tokyo), which was almost 100 km (62.137 miles) away.
Records of eruption
Sixteen eruptions of New Fuji have been recorded since 781. Many of the eruptions occurred in the
Heian era
The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japanese. ...
, with twelve eruptions between 800 and 1083. Sometimes inactive periods between eruptions lasted for hundreds of years, as in the period between 1083 and 1511, when no eruptions were recorded for over 400 years. At present, there have been no eruptions since the Hoei eruption in 1707–1708, around 300 years ago.
Current eruptive danger
Scientists study the activity of the magma rising by measuring CO
2 emissions in the deeper parts of the volcano. Studies from before the 2011
Tohoku earthquake show the CO
2 emissions below 5 gCO
2/m
3/day, which is the detection limit. If the emissions rise above 5 gCO
2/m
3/day then seismic activity is occurring and an eruption could possibly take place. According to a five-stage evolutionary model for the release of volcanic gas, Mt. Fuji would be considered stage I. Magma is at a considerable depth and no emissions of gases can be observed regularly.
Following the 2011 Tōhoku earthquake and tsunami, much attention was given to the volcanic reaction of Mount Fuji. Experts have found that the internal pressure of the Mount Fuji magma chamber has increased to an estimated 1.6 megapascals, raising speculation over the possibility of an eruption. The financial damage to Japan from a Fuji eruption is estimated at ¥2.5 trillion (about $25 billion).
See also
*
Hōei eruption of Mount Fuji
was a after Genroku and before Shōtoku''.'' This period spanned the years from March 1704 through April 1711. The reigning emperors were and .
Change of era
* 1704 : In reaction to the Great Genroku earthquake in Genroku 16, the era name w ...
*
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 Archipelag ...
Notes
References
* , "''Mount Fuji - All About Its Nature''", written by 1992
* Titsingh, Isaac. (1834).
iyun-sai_Rin-siyo/Hayashi_Gahō,_1652.html" ;"title="Hayashi_Gahō.html" ;"title="iyun-sai Rin-siyo/Hayashi Gahō">iyun-sai Rin-siyo/Hayashi Gahō, 1652">Hayashi_Gahō.html" ;"title="iyun-sai Rin-siyo/Hayashi Gahō">iyun-sai Rin-siyo/Hayashi Gahō, 1652 ''Nipon o daï itsi ran; ou
Annales des empereurs du Japon.' Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland.
External links
* {{cite web, url= http://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/souran_eng/volcanoes/055_fujisan.pdf Fujisan , title=Fujisan (Mount Fuji) - Japan Meteorological Agency
Fujisan (Mount Fuji)- Smithsonian Institution: Global Volcanism Program
Izu–Bonin–Mariana Arc
Volcanoes of Honshū
Mount Fuji