Sakurajima ( ja, 桜島, literally "

Cherry Blossom A cherry blossom, also known as Japanese cherry or sakura, is a flower of many trees of Prunus, genus ''Prunus'' or Prunus subg. Cerasus, ''Prunus'' subg. ''Cerasus''. They are common species in East Asia, including China, Korea and especia ...

Island") is an active

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 peri ...

, formerly an

island An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An isla ...

and now a peninsula, in

Kagoshima Prefecture is a prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,599,779 (1 January 2020) and has a geographic area of 9,187 km2 (3,547 sq mi). Kagoshima Prefecture borders Kumamoto P ...

Kyushu is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

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 n ...

. The

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 ...

flows of the 1914 eruption connected it with the Ōsumi Peninsula. It is the most active volcano in Japan. As of April 2021, the volcanic activity still continues, dropping

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...

on the surroundings. Earlier eruptions built the white sand highlands in the region. On September 13, 2016, a team of experts from

Bristol University , mottoeng = earningpromotes one's innate power (from Horace, ''Ode 4.4'') , established = 1595 – Merchant Venturers School1876 – University College, Bristol1909 – received royal charter , type ...

and the Sakurajima Volcano Research Centre in Japan suggested that the volcano could have a major eruption within 30 years; since then two eruptions have occurred. Sakurajima is a

. Its

summit A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topographic terms acme, apex, peak (mountain peak), and zenith are synonymous. The term (mountain top) is generally used only for a m ...

has three peaks, ''Kita-dake'' (northern peak), ''Naka-dake'' ( central peak) and ''Minami-dake'' (southern peak) which is active now. Kita-dake is Sakurajima's highest peak, rising to above

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardis ...

. The mountain is in a part of

Kagoshima Bay also known as Kinkō Bay, is a deep inlet of the East China Sea on the coast of Japan.''Merriam Webster's Geographical Dictionary, Third Edition'', p. 562. Kagoshima Bay is on the south coast of the island of Kyūshū. The port city of Kag ...

known as Kinkō-wan. The former island is part of the

city A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be def ...

Kagoshima , abbreviated to , is the capital city of Kagoshima Prefecture, Japan. Located at the southwestern tip of the island of Kyushu, Kagoshima is the largest city in the prefecture by some margin. It has been nicknamed the "Naples of the Eastern wor ...

.Nussbaum
"Kagoshima prefecture" at p. 447
The surface of this volcanic peninsula is about .

History

Geological history

Sakurajima is in the 25 km (15 mi)-wide

Aira caldera Aira Caldera is a gigantic volcanic caldera that is located on the southern end of Kyushu, Japan. It is believed to have been formed about 30,000 years ago with a succession of pyroclastic surges. It is currently the place of residence to over 9 ...

, which formed in an enormous "blow-out-and-cave-in" eruption around 22,000 years ago. Several hundred cubic kilometres of

ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

and

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular v ...

were ejected, causing the

magma chamber A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it up ...

underneath the erupting vents to collapse. The resulting caldera is over across.

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 r ...

fell as far as from the volcano. Sakurajima is a modern active vent of the same Aira caldera volcano. Sakurajima was formed by later activity within the caldera, beginning about 13,000 years ago. It is about south of the centre of the caldera. Its first eruption in recorded history was in 963 AD. Most of its eruptions are strombolian, affecting only the summit areas, but larger plinian eruptions have occurred in 1471–1476, 1779–1782 and 1914. Volcanic activity at ''Kita-dake'' ended around 4,900 years ago: later eruptions have been centered on ''Minami-dake''. Since 2006, activity has centred on Showa crater, to the east of the summit of Minami-dake.

1914 eruption

Buried torii near Kurokami-Cho, Kagoshima

The 1914 eruption began on January 11 and was the most powerful in twentieth-century Japan. The volcano had been dormant for over a century until 1914. Almost all residents had left the island in the previous days; several large

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, fr ...

s had warned them that an eruption was imminent. Initially, the eruption was very explosive, generating

eruption column An eruption column or eruption plume is a cloud of super-heated ash and tephra suspended in gases emitted during an explosive volcanic eruption. The volcanic materials form a vertical column or plume that may rise many kilometers into the ai ...

s and

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, but after a very large earthquake on January 12, and another the day after, it became effusive, generating a large lava flow. The January 12 earthquake killed 35, and in total, 58 people died.

Lava flow 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 ...

s filled the narrow strait between the island and the mainland, turning it into a peninsula. Lava flows are rare in Japan—because the

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

content of the

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 natura ...

s is high, explosive eruptions are far more common—but the lava flows at Sakurajima continued for months. The island grew, engulfing several smaller islands nearby, and eventually became connected to the mainland by a narrow isthmus. Parts of

became significantly shallower, and it made tides higher. During the last stages of the eruption, emptying of the underlying magma chamber sank the centre of the Aira Caldera by about . This showed that Sakurajima draws its magma from the same magma reservoir that fed the ancient caldera-forming eruption. The eruption partly inspired a 1914 movie, '' The Wrath of the Gods'', centering on a

family curse A curse (also called an imprecation, malediction, execration, malison, anathema, or commination) is any expressed wish that some form of adversity or misfortune will befall or attach to one or more persons, a place, or an object. In particular ...

that ostensibly causes the eruption.

Recent activity

Sakurajima's activity became more prominent in 1955, and the volcano has been erupting almost constantly ever since. Thousands of small explosions happen each year, throwing ash to heights of up to a few kilometers above the mountain. The Sakurajima Volcano Observatory was set up in 1960 to monitor these eruptions. Monitoring of the volcano and predictions of large eruptions are particularly important because it is in a densely populated area, with the city of Kagoshima's 680,000 residents just a few kilometers from the volcano. The city conducts regular evacuation drills, and a number of shelters have been built where people can take refuge from falling volcanic debris. In light of the dangers it presents to nearby populations, Sakurajima was designated a Decade Volcano in 1991, identifying it as worthy of particular study as part of the

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoni ...

' International Decade for Natural Disaster Reduction. Sakurajima is part of the Kirishima-Yaku National Park, and its lava flows are a major tourist attraction. The area around Sakurajima contains several hot spring resorts. One of the main agricultural products of Sakurajima is a huge basketball-sized white radish (''

Sakurajima daikon The Sakurajima radish or Sakurajima daikon ( ja, , ''Sakurajima daikon'') is a special cultivar of the Japanese radish named for its original place of cultivation, the former island of Sakurajima in Japan's Kagoshima Prefecture. It is the biggest ...

''). On March 10, 2009, Sakurajima erupted, sending debris up to . An eruption had been expected following a series of smaller explosions over the weekend. It is not thought there was any damage caused. An eruption occurred from the Minami-dake summit crater at 5:38 on Sunday, August 9, 2010, sending debris up to 5000 m (16,000 ft). In 2011 and 2012, Sakurajima experienced several significant eruptions; volcanic activity continued into 2013. Photographer Martin Rietze captured a rare picture of lightning within the ash plume in January 2013 during a magma ejection, which was a NASA astronomy pic of the day in March 2013. On August 18, 2013, the volcano erupted from

Showa crater Showa crater is a feature on Sakurajima mountain volcano, in southern Japan. On 18 August 2013, the volcano erupted from Showa crater and produced its highest recorded plume of ash since 2006, rising high and causing darkness and significant ash ...

and produced its highest recorded plume of ash since 2006, rising 5,000 metres high and causing darkness and significant ash falls on the central part of Kagoshima city. The eruption occurred at 16:31 and was the 500th eruption of the year. In August 2015, Japan's meteorological agency issued a level 4 emergency warning, which urges residents to prepare to evacuate. Scientists warned that a major eruption could soon take place at the volcano; it eventually did erupt around 20:00 on February 5, 2016. After a long pause of eruptions at the vent, the eruptions abruptly stopped there and returned to the Showa crater, on April 4, 2016, some 8–9 days preceding major

earthquakes 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, fro ...

on the Median Tectonic Line near Kumamoto, Japan. Then, three months later, on July 26, it spewed volcanic ash into the air. On October 3, 2020, at 07:35 UTC, the volcano erupted once again, this time from the Aira caldera. A volcanic ash advisory for aviation was issued by the Volcanic Ash Advisory Center Tokyo (VAAC) at 07:43 UTC, showing the ash cloud to be stationary and reaching FL100 (10,000 feet). On July 24, 2022, at 20:05 JST, an explosive eruption occurred at the summit crater of the volcano, and cinders scattered up to 2.5 km from the crater. Following this eruption, at 20:50 JST, the Japan Meteorological Agency raised the eruption alert level from Level 3 to Level 5, the highest level, and urged maximum precaution and evacuation. This was the first time an eruption alert level 5 has been issued for Sakurajima.

Timeline

File:1914-Sakurajima-eruption.jpg, Eruption in 1914 File:1974 Japan Sakurajima.jpg, Sakurajima eruption in 1974 File:Sakura-jima from space.jpg, Space radar image of Sakurajima in 1994 File:Sakurajima21.JPG, 2004 File:Sakurajima 20091003.jpg, 2009 File:Kagoshima-shi-sakurajima-japan- 20100114- 013.jpg, 2010 File:Sakurajima September 2013 2.jpg, Eruption on 2013-09-23 File:The Famous Scenes of the Sixty States 66 Osumi.jpg, A print of Sakurajima by

Hiroshige Utagawa Hiroshige (, also ; ja, 歌川広重 ), born Andō Tokutarō (; 1797 – 12 October 1858), was a Japanese ''ukiyo-e'' artist, considered the last great master of that tradition. Hiroshige is best known for his horizontal-format l ...

File:Sakurajima 2019-07-01.jpg, Sakurajima from a ferry in Kagoshima Bay, 2019-07-01 File:Over_Sakurajima_Volcano_(4278148645).jpg, Seen from an aircraft in 2009 File:2020-01-29, Sentinel-1 AWS (S1-AWS-IW-VVVH), VV - decibel gamma0 - orthorectified.jpg, Satellite view in January 2020 File:Sakurajima Volcano, Kagoshima Prefecture, Kyushu, Japan - April 26th, 2021 (51141772727).jpg, April 2021

Culture

''Sakurajima'' is the title of a 1946 short story, written by the Japanese writer Haruo Umezaki, about a disillusioned Navy officer stationed on the volcano island towards the end of World War II as American air force planes bomb Japan. The story is based on Umezaki's own experience; he was stationed in a military cipher base in the nearby Prefecture city of

. ''Sakurajima'' was also the name of Japanese singer

Tsuyoshi Nagabuchi is a Japanese singer-songwriter, actor, poet, and human-rights advocate, who is a prominent figure in Japanese popular music. He has sold more than 20 million records worldwide and has appeared in movies and television dramas. His wife Etsu ...

's song. In 2004, Nagabuchi held an at a quarry of Sakurajima that attracted an audience of 75,000. After the concert, a statue showing Nagabuchi

screaming A scream is a loud vocalization in which air is passed through the vocal cords with greater force than is used in regular or close-distance vocalisation. This can be performed by any creature possessing lungs, including humans. A scream is o ...

with a guitar was installed on the site of the concert.

Notes

References

* Townley, S.D. (1915)
"Seismographs at the Panama-Pacific Exposition,"
''Bulletin of the Seismological Society of America.'' Stanford, California: Seismological Society of America. * ''Teikoku's Complete Atlas of Japan'', Teikoku-Shoin Co., Ltd. Tokyo 1990

External links

Sakurajima: National catalogue of the active volcanoes in Japan
- Japan Meteorological Agency

- Kyoto University
Aira / Sakurajima, Global Volcanic Program

Footage of the March 2009 eruption
- BBC
Schoolchildren in Kagoshima wearing helmets to protect against stones thrown out by the nearby Sakurajima volcano (which is in background)

Schoolchildren and their teacher wearing helmets

Google Earth air view

Google Earth ground view approaching Sakurajima from the mainland

Smithsonian Institution's Global Volcanism Program (GVP) (entry for Aira /Sakurajima)
{{Authority control Landforms of Kagoshima Prefecture Volcanoes of Kyushu Stratovolcanoes of Japan Subduction volcanoes Decade Volcanoes Active volcanoes VEI-6 volcanoes 20th-century volcanic events Former islands Volcanic eruptions in 2022