June 21, 1983 Tsunami: N. Honshu Island, Japan

Name: June 21, 1983 Tsunami: N. Honshu Island, Japan
Start: 1983-06-21
Location: N. Honshu Island, Japan

June 21, 1983 · 1 m · Definite tsunami

A tsunami caused by a magnitude 6.9 earthquake began at N. Honshu Island, Japan on June 21, 1983 at 06:25:27 UTC. The water rose as high as 1 meters. Its effects were recorded at 27 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: June 21, 1983, 06:25:27 UTC
Source: N. Honshu Island, Japan
Cause: Earthquake
Earthquake: Magnitude 6.9, 10 km deep
Maximum water height: 1 m (3.3 ft)
Runups recorded: 27
Waters: Ocean
How certain: Definite tsunami
Source location: 41.346° N, 139.099° E

The toll

Damage: Limited (under about $1 million) 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.

A magnitude 6.9 Mw (USGS) aftershock of the May 26 earthquake at 6:25 UT caused damage on northern Hoshu, Japan along with a tsunami at Akita. A fishing boat was overturned at Aomori but no injuries occurred.

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	Measured by
Yoshioka	Japan	97	0.42	Tide gauge (half the maximum wave height)
Fukaura	Japan	104	0.11	Tide gauge (half the maximum wave height)
Esashi	Japan	104	0.3	Tide gauge (half the maximum wave height)
Minmaya	Japan	113		Tide gauge (half the maximum wave height)
Noshiroko	Japan	147	0.21	Tide gauge (half the maximum wave height)
Oga	Japan	165	0.1	Tide gauge (half the maximum wave height)
Funakawaminato	Japan	176	0.08	Tide gauge (half the maximum wave height)
Akita	Japan	198	0.08	Tide gauge (half the maximum wave height)
Iwanaiko	Japan	216	0.33	Tide gauge (half the maximum wave height)
Oshoro	Japan	252	0.16	Tide gauge (half the maximum wave height)
Ishikariwanshinko	Japan	277	0.15	Tide gauge (half the maximum wave height)
Sakata	Japan	277	0.11	Tide gauge (half the maximum wave height)
Nezugaseki	Japan	311	0.09	Tide gauge (half the maximum wave height)
Awashima	Japan	320	0.09	Tide gauge (half the maximum wave height)
Iwafuneko	Japan	352	0.13	Tide gauge (half the maximum wave height)
Ryotsuko	Japan	367	0.16	Tide gauge (half the maximum wave height)
Ogi	Japan	398	0.06	Tide gauge (half the maximum wave height)
Kashiwazakiko	Japan	444	0.13	Tide gauge (half the maximum wave height)
Senposhigyoko	Japan	448	0.21	Tide gauge (half the maximum wave height)
Kutsugatako	Japan	458	0.13	Tide gauge (half the maximum wave height)
Naoetsuko	Japan	468	0.15	Tide gauge (half the maximum wave height)
Wajima	Japan	477	0.05	Tide gauge (half the maximum wave height)
Wakkanai	Japan	498	0.07	Tide gauge (half the maximum wave height)
Mikuni	Japan	621	0.05	Tide gauge (half the maximum wave height)
Maizuru	Japan	727	0.05	Tide gauge (half the maximum wave height)
Saigo	Japan	760	0.07	Tide gauge (half the maximum wave height)
Sakai	Japan	821	0.07	Tide gauge (half the maximum wave height)

Every tsunami in 1983 The 1900s 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 2145.