The 1854 Nankai earthquake occurred at about 16:00 local time on 24 December. It had a

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

of 8.4 and caused a damaging

tsunami A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, ...

. More than 30,000 buildings were destroyed and there were at least 3,000 casualties. It was the second of the three Ansei great earthquakes; the 1854 Tōkai earthquake of identical magnitude had hit northeast the previous morning, and the third 1855 Edo earthquake would strike less than a year later.

Background

The southern coast of Honshu runs parallel to the

Nankai Trough The is a submarine trough located south of the Nankaidō region of Japan's island of Honshu, extending approximately offshore. The underlying fault, the ''Nankai megathrust,'' is the source of the devastating Nankai megathrust earthquakes, ...

, which marks the

subduction Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

of the

Philippine Sea plate The Philippine Sea plate or the Philippine plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines. Most segments of the Philippines, including northern Luzon, are part of ...

beneath the Eurasian plate. Movement on this convergent plate boundary leads to many earthquakes, some of them of the megathrust type. The Nankai megathrust has five distinct segments (A–E) that can rupture independently, the segments have ruptured either singly or together repeatedly over the last 1300 years. Megathrust earthquakes on this structure tend to occur in pairs, with a relatively short time gap between them. In addition to the two events in 1854, there were similar earthquakes in 1944 and 1946. In each case the northeastern segment ruptured before the southwestern segment.

Damage

The damage due to the earthquake was severe with 5,000 houses being destroyed and 40,000 houses badly damaged. A further 6,000 homes were damaged by fire. The tsunami washed away a further 15,000 houses and a total of 3,000 people died from either the earthquake or the tsunami. The death toll associated with the tsunami was less than would be expected in comparison to the 1707 tsunami, because many people had left the coastal area following the large earthquake the previous day. In Hiro (now

Hirogawa file:Inamura no hi no yakata.jpg, 270px, Inamura no hi no yakata is a List of towns in Japan, town in Arida District, Wakayama, Arida District, Wakayama Prefecture, Japan. , the town had an estimated population of 6,778 in 2,833 households and a p ...

), Goryo Hamaguchi set fires using rice straw to help guide villagers to safety. This story was turned into "A living god" by the Greek-born writer

Lafcadio Hearn was a Greek-born Irish and Japanese writer, translator, and teacher who introduced the culture and literature of Japan to the Western world. His writings offered unprecedented insight into Japanese culture, especially his collections of legend ...

Characteristics

Earthquake

Much of southwestern Honshu, Shikoku and

Kyūshū is the third-largest island of Japan's four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa and the other Ryukyu (''Nansei'') Islands). In the past, it has been known as , and . The historical regio ...

experienced shaking of 5 or more on the JMA scale, with most of Shikoku and nearby coastal areas of

Kansai The or the lies in the southern-central region of Japan's main island Honshū. The region includes the prefectures of Nara, Wakayama, Kyoto, Osaka, Hyōgo and Shiga, often also Mie, sometimes Fukui, Tokushima and Tottori. The metropoli ...

suffering an intensity of 6.

Tsunami

On Shikoku, the greatest inundation heights were 7.5 m in Mugi, 7.5 m in Kamikawaguchi ( Japanese: 上川口) of

Kuroshio The , also known as the Black Current or is a north-flowing, warm ocean current on the west side of the North Pacific Ocean basin. It was named for the deep blue appearance of its waters. Similar to the Gulf Stream in the North Atlantic, the Ku ...

, 7.2 m at Asakawa on the

Tokushima is a Prefectures of Japan, prefecture of Japan located on the island of Shikoku. Tokushima Prefecture has a population of 682,439 (1 February 2025) and has a geographic area of 4,146 Square kilometre, km2 (1,601 sq mi). Tokushima Prefecture b ...

coast, 7.4 m at Usa, 8.4 m at Ōnogō in the Susaki area, 8.3 m at Kure on the Kōchi coast and 5 m at both Hisayoshiura and Kaizuka on the coast of Ehime. A tsunami was observed in

Shanghai Shanghai, Shanghainese: , Standard Chinese pronunciation: is a direct-administered municipality and the most populous urban area in China. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

, and a water surge of about 2 to 3 '' Chi'' was recorded in the

Huangpu River The Huangpu (), formerly romanized as Whangpoo, is a river flowing north through Shanghai. The Bund and Lujiazui are located along the Huangpu River. The Huangpu is the biggest river in central Shanghai, with the Suzhou Creek being its ...

Background

Damage

Characteristics

Earthquake

Tsunami

See also

References

Further reading