Tsunamis in 684

November 29, 684 Tsunami: Nankaido, Japan

November 29, 684 · 3 m · Deaths: many · Definite tsunami

A tsunami caused by a magnitude 8.4 earthquake began at Nankaido, Japan on November 29, 684. The water rose as high as 3 meters. Its effects were recorded at 2 places.

Where the waves reached

The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.

  • Under 1 m
  • 1 to 3 m
  • 3 to 10 m
  • 10 to 30 m
  • 30 m and more
  • Height not recorded

Tsunami warnings in force

The tsunami

Date
November 29, 684
Source
Nankaido, Japan
Cause
Earthquake
Earthquake
Magnitude 8.4
Maximum water height
3 m (9.8 ft)
Runups recorded
2
Tsunami intensity (Soloviev-Imamura)
1
Tsunami magnitude (Iida)
1.6
Waters
Ocean
How certain
Definite tsunami
Source location
32.500° N, 134.000° E

The toll

Deaths
Many (about 101 to 1,000)
Damage
Severe (about $5 to $25 million)

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

What the record says

NCEI’s account, from the sources it cites.

684, November 29. Many boats sunk. Many shrines, temples and houses damaged. 11.3-13.7 km2 of land sank with two villages in Tosa Province. Iyo (Matsuyana) and Kanayama (Shirahama, Kii) hot spring stopped. Tsunami inundated at Kumano. Atashika, 2-3m, and affected N. Izu. (reference #150)

684, November 29. There was a tsunami which was most intensive on the coast of Kochi Prefecture. About 12 km2 with two villages went under water. Where this occurred is unknown, but it may have been on the coast of Tosa Bay, in the region of Urado Inlet (the coast also subsided in the vicinity of Urado during the strong earthquake of 1707).

(reference #414)

684, November 29. A vast area of land in the province of Tosa was lost under the sea; sea waves resulted. (reference #1897)

Most authors list the date as Nov 29, but Oct 14 (uncorrected Japanese date) and Nov 24 are also used. (from reference #79)

Every runup

Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.

WhereCountryKm from sourceWater height, mInland, mMeasured byFirst wave, UTCDeaths
TosaJapan124Eyewitness observation of water height
AtashikaJapan2553Eyewitness observation of water height

More

Every tsunami in 684The 600sTsunamis of JapanThe earthquakeThis day in weather historyAlerts in force

Sources

Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 53.