May 26, 1828 Tsunami: Amakusa Sea, Japan

Name: May 26, 1828 Tsunami: Amakusa Sea, Japan
Start: 1828-05-26
Location: Amakusa Sea, Japan

May 26, 1828 · Definite tsunami

A tsunami caused by a magnitude 6.4 earthquake began at Amakusa Sea, Japan on May 26, 1828. 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

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: May 26, 1828
Source: Amakusa Sea, Japan
Cause: Earthquake
Earthquake: Magnitude 6.4
Runups recorded: 2
Waters: Ocean
How certain: Definite tsunami
Source location: 32.600° N, 129.900° E

The toll

The record gives no deaths, injuries or damage for this tsunami.

What the record says

NCEI’s account, from the sources it cites.

Reference #414:

May 26 (Dec 18), 1828. There was an earthquake in

Chachibana Bay or at Amakusa-Nada. It was supposedly accompanied by an "underwater disturbance" and waves on the coast of Nagasaki Prefecture and the Amakusa Islands. Epicenter 37.6 N., 138.9 E; M=6.9.

Reference #150:

May 26, 1828, 32.6 N, 129.9 E, magnitude 6.4. Many aftershocks. Various places inundated.

Reference #79:

May 26 (Dec 18), 1828. 37.6 N, 138.9 E, magnitude 6.9, Chijiwa Bay or Amakusa Sea. Observation: Japan - Kyushu, Nagasaki ~ Amakusa. Earthquake said to have been accompanied by submarine disturbance and waves. This event and an undated flood are the only ones found in Japanese records that might have been the basis for Milne's report of sea waves accompanying the Echigo (Niigata) quake of Dec. 18. Heck erroneously listed the Echigo site of the quake as the site of the reported tsunami.

Reference #132:

Dec 18, 1828. Japan, Echigo, Sea wave at Kiushu.

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
Amakusa Islands	Japan	0			Eyewitness observation of water height
Nagasaki	Japan	15			Eyewitness observation of water height

Every tsunami in 1828 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 667.