March 21, 1982 Tsunami: Hokkaido Island, Japan

Name: March 21, 1982 Tsunami: Hokkaido Island, Japan
Start: 1982-03-21
Location: Hokkaido Island, Japan

March 21, 1982 · 1.3 m · 110 deaths · $1 million · Definite tsunami

A tsunami caused by a magnitude 6.9 earthquake began at Hokkaido Island, Japan on March 21, 1982 at 02:32:07 UTC. The water rose as high as 1.3 meters. Its effects were recorded at 31 places. It killed 110 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: March 21, 1982, 02:32:07 UTC
Source: Hokkaido Island, Japan
Cause: Earthquake
Earthquake: Magnitude 6.9, 44 km deep
Maximum water height: 1.3 m (4.3 ft)
Runups recorded: 31
Tsunami magnitude (Iida): 0.4
Waters: Ocean
How certain: Definite tsunami
Source location: 42.158° N, 142.361° E

The toll

Deaths: 110 with the earthquake or eruption that caused it
Injuries: 100 with the earthquake or eruption that caused it
Damage: $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.

The max rise of water above calm sea level was 45 cm in Mitsuishi. Tsunami was recorded at the Hokkaido coast and the northeast coast of Honshu.

Tsunami (80 cm peak to trough) recorded at Urakawa, (24 cm peak to trough) at Hachinoe. (reference #1053)

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	First wave, UTC
Harutachi	Japan	17	0.18	Eyewitness observation of water height
Higashishizunai	Japan	17	0.2	Eyewitness observation of water height
Kerimaigyoko	Japan	22	0.1	Eyewitness observation of water height
Seppu	Japan	26	0.28	Eyewitness observation of water height
Atsuga	Japan	33	0.08	Eyewitness observation of water height
Urakawa	Japan	34	0.78	Tide gauge (half the maximum wave height)
Tomihama	Japan	47	0.15	Eyewitness observation of water height
Samani	Japan	48	0.4	Eyewitness observation of water height
Horoizumi	Japan	67	0.2	Eyewitness observation of water height
Erimo	Japan	78	0.33	Tide gauge (half the maximum wave height)
Shoya	Japan	79	0.14
Shoyagyoko	Japan	79	0.3	Tide gauge (half the maximum wave height)
Hiroo	Japan	80	0.14	Tide gauge (half the maximum wave height)	day 21, 03:34
Tomakomainishiko	Japan	81	0.16	Tide gauge (half the maximum wave height)
Tokachiko	Japan	82	0.18	Tide gauge (half the maximum wave height)
Muroran	Japan	118	0.09	Tide gauge (half the maximum wave height)
Hakodate	Japan	144	0.2	Tide gauge (half the maximum wave height)
Moriko	Japan	146	0.2	Tide gauge (half the maximum wave height)
Kushiro	Japan	188	0.1	Tide gauge (half the maximum wave height)
Hachinohe	Japan	193	0.26	Tide gauge (half the maximum wave height)
Hachinohe (Kensetsukyoku)	Japan	195	0.3	Tide gauge (half the maximum wave height)
Kujiko	Japan	222	0.12	Tide gauge (half the maximum wave height)
Kuji	Japan	227	0.14
Akkeshigyoko	Japan	227	0.05	Tide gauge (half the maximum wave height)
Shimanokoshigyoko	Japan	253	0.08	Tide gauge (half the maximum wave height)
Miyako	Japan	280	0.1	Tide gauge (half the maximum wave height)
Hanasaki	Japan	291	0.07	Tide gauge (half the maximum wave height)
Kamaishi	Japan	324	0.08	Tide gauge (half the maximum wave height)
Ofunato	Japan	353	0.09	Tide gauge (half the maximum wave height)
Enoshima	Japan	422	0.03	Tide gauge (half the maximum wave height)
Ayukawa	Japan	435	0.08	Tide gauge (half the maximum wave height)

Every tsunami in 1982 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 2135.