Sakurajima (, ) is an active

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

, formerly an

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

and now a peninsula, in

Kagoshima Prefecture is a Prefectures of Japan, prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,527,019 (1 February 2025) and has a geographic area of 9,187 Square kilometre, km2 (3,547 Square m ...

Kyushu is the third-largest island of Japan's Japanese archipelago, four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa Island, Okinawa and the other Ryukyu Islands, Ryukyu (''Nansei'') Ryukyu Islands, Islands ...

, Japan. 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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

flows of the 1914 eruption connected it with the

Ōsumi Peninsula image:Osumi Peninsula Kagoshima Japan SRTM.jpg, 261x261px, Satellite image of Ōsumi Peninsula The projects south from the Japanese island of Kyūshū and includes the southernmost point on the island, Cape Sata. Its east coast lies on the Pacifi ...

. It is the most active volcano in Japan. , the volcanic activity still continues, dropping

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

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

Bristol University The University of Bristol is a public research university in Bristol, England. It received its royal charter in 1909, although it can trace its roots to a Merchant Venturers' school founded in 1595 and University College, Bristol, which had ...

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 ...

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 mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

. 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 Kagoshi ...

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

city A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agree ...

Kagoshima , is the capital Cities of Japan, city of Kagoshima Prefecture, Japan. , the city had an estimated population of 583,966 in 285,992 households, and a population density of 1100 persons per km2. The total area of the city is . Etymology While the ...

which is only 4km across the bay.Nussbaum
"Kagoshima prefecture" at p. 447
The surface of this volcanic peninsula is about . Sakurajima has a population of a few thousand residents, formerly incorporated as Sakurajima town, with a number of schools, shrines, and shops on the island. It is serviced by the Sakurajima Ferry which runs 24/7. It is a tourist destination known for its onsen, local pottery made from volcanic ash, and produce such as the Sakurajima daikon radish and Sakurajima komikan orange which grow in the immensely fertile volcanic soil. Sakurajima has many natural areas and the ecosystems in different areas where recent eruptions have taken place have been researched as an example of

ecological succession Ecological succession is the process of how species compositions change in an Community (ecology), ecological community over time. The two main categories of ecological succession are primary succession and secondary succession. Primary successi ...

History

Geological history

Sakurajima is in the 25 km (15 mi)-wide Aira caldera, which formed in an enormous "blow-out-and-cave-in" eruption around 22,000 years ago. Several hundred cubic kilometres of ash and

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

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 u ...

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

Tephra Tephra is fragmental material produced by a Volcano, 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, ...

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 Plinian eruptions or Vesuvian eruptions are Volcano, volcanic Types of volcanic eruptions, eruptions characterized by their similarity to the eruption of Mount Vesuvius in 79 AD, which destroyed the ancient Roman cities of Herculaneum and Pompei ...

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

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 earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

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 Volcanic ash, ash and tephra suspended in volcanic gas, gases emitted during an explosive eruption, explosive volcanic eruption. The volcanic materials form a vertical column or Plu ...

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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

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 , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...

content of the

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

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 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 the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...

' 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''). 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. On August 18, 2013, the volcano erupted from Showa crater 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 earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they c ...

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. On February 9, 2023, an eruption occurred at the Showa crater on Sakurajima at 10:52 JST. The plumes had risen to 1000 meters at 11:10 JST, according to the Kagoshima Meteorological Office. People in a 2-km radius were sent a warning by the local weather observatory against pyroclastic flows and falling rocks. On February 14, 2024, an eruption occurred at the Minamidake crater on Sakurajima at 18:33 JST, emitting plumes of over five kilometers in height and spewing rocks as far as 1.3 kilometers away.

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 or , 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 landscape series '' The Fifty-three Stations ...

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'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/hard speech production, 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 h ...

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 Volcanic eruptions in 2023