December 9, 1802 Tsunami: NW. Honshu Island, Japan

Name: December 9, 1802 Tsunami: NW. Honshu Island, Japan
Start: 1802-12-09
Location: NW. Honshu Island, Japan

December 9, 1802 · 19 deaths · 1,060 houses destroyed · Definite tsunami

A tsunami caused by a magnitude 6.6 earthquake began at NW. Honshu Island, Japan on December 9, 1802 at 05:00 UTC. Its effects were recorded at 1 place. It killed 19 people, counting the earthquake or eruption that caused it.

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

Travel times

How long the first wave took to reach each part of the ocean, one line for each hour up to 24, estimated from the source and the depth of the sea.

The travel times are computed in your browser, which needs JavaScript.

1 to 4 hours
5 to 6 hours
7 to 14 hours
15 hours and more

Computed in your browser the way NOAA’s own travel time maps are: the wave travels at the square root of gravity times the depth, over NOAA’s ETOPO1 depths averaged to a 10 arc-minute grid. Checked against NOAA NCEI’s maps for 21 tsunamis over the first 24 hours, these lines fall within 10 minutes of NCEI’s at half the points compared and within 52 minutes at 9 in 10. They give when the first wave could arrive, not how high it is; bays, harbors and island chains finer than the grid can see it later. Not for use in a warning: see tsunami.gov.

The tsunami

Date: December 9, 1802, 05:00 UTC
Source: NW. Honshu Island, Japan
Cause: Earthquake
Earthquake: Magnitude 6.6
Runups recorded: 1
Tsunami magnitude (Iida): 0
Waters: Ocean
How certain: Definite tsunami
Source location: 37.700° N, 138.300° E

The toll

Deaths: 19 with the earthquake or eruption that caused it
Damage: Severe (about $5 to $25 million) with the earthquake or eruption that caused it
Houses destroyed: 1,060 with the earthquake or eruption that caused it

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.

Reference #414:

December 9 (mistakenly 28), 1802, at about 10:00 [local time] there was an earthquake on the southwest of Sado Island. It was accompanied by an elevation of the coast of the island on a stretch of 25 km from Cape Sawasaki in the west to Akadomari in the east. The greatest rise, equal to 2-2 1/2 m, was apparently registered at Ogi. Inside Ogi Port, the water retreated from shore and the bottom was exposed for a distance of about 100 m. The residents, frightened by the ebb tide, feared a tsunami. However, damage from a tsunami is nowhere mentioned. Apparently, there were no tsunami waves, at least no strong ones, and only an elevation of the island took place, accompanied by buckling.

A very strong earthquake occurred at 14:00. It caused great destruction to homes and monuments. Ogi suffered most of all. Of 453 homes here, 328 homes were destroyed or burned; four people died in the earthquake and 14 people died in the fire. There was also destruction at

Aikawa. The total damage on Sado Island, excluding Ogi, numbered as follows: 732 destroyed homes, 1,423 damaged homes. Epicenter 37.8 N, 138.4 E, magnitude 6.6.

Probability 1.

Reference #150:

Before shock, land upheaved, 2m at Ogi where tsunami took place. 450 houses completely destroyed at Ogiminato. 19 deaths, 732 houses destroyed, 328 houses disappeared by fire in total. Epicenter 37.7 N, 138.3 E, magnitude 6.6.

Reference #79:

Dec 9 (28), 1802. 37.8 N, 138.4 E, magnitude 6.6, N. Chubu. Observation: Japan, N.W. Honshu, Niigata.

Every runup

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

Where	Country	Km from source	Water height, m	Inland, m	Measured by	First wave, UTC	Deaths
Ogi	Japan	104			Eyewitness observation of water height

Every tsunami in 1802 The 1800s Tsunamis of Japan The earthquake This day in weather history Alerts 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 588.