November 5, 1938 Tsunami: Sanriku, Japan
A tsunami caused by a magnitude 7.7 earthquake began at Sanriku, Japan on November 5, 1938 at 08:43:21 UTC. The water rose as high as 0.57 meters. Its effects were recorded at 17 places. It killed 1 person, 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
The tsunami
- Date
- November 5, 1938, 08:43:21 UTC
- Source
- Sanriku, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 7.7, 30 km deep
- Maximum water height
- 0.57 m (1.9 ft)
- Runups recorded
- 17
- Tsunami intensity (Soloviev-Imamura)
- -0.5
- Tsunami magnitude (Iida)
- 0.1
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 37.100° N, 141.700° E
The toll
- Deaths
- 1 with the earthquake or eruption that caused it
- Damage
- Limited (under about $1 million) with the earthquake or eruption that caused it
- Houses destroyed
- 20 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.
1938, November 5, at 17:43 [local time] there was a very strong earthquake with source off the coast of Fukushima Prefecture. It was accompanied by a tsunami which was registered on the coast of the Sanriku area, Fukushima and Chiba Prefectures and Hokkaido Island. The predominant period of oscillations on the tide gauge records is 15 to 30 minutes. (reference #414)
Reference #150 lists epicenter 37.2 N, 141.7 E, depth 30 km, magnitude 7.7, one death, 20 houses collapsed.
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 |
|---|---|---|---|---|---|---|---|
| Onahama | Japan | 74 | 0.54 | Tide gauge (half the maximum wave height) | day 5, 09:15 | ||
| Iwai (Oarai) | Japan | 131 | 0.44 | Tide gauge (half the maximum wave height) | |||
| Tanaka (Nakaminato) | Japan | 131 | 0.21 | Tide gauge (half the maximum wave height) | |||
| Ayukawa | Japan | 134 | 0.52 | Tide gauge (half the maximum wave height) | day 5, 09:26 | ||
| Hanabuchi (Shiogama) | Japan | 142 | 0.57 | Tide gauge (half the maximum wave height) | day 5, 09:53 | ||
| Oshima (Shiogamako) | Japan | 147 | 0.16 | Tide gauge (half the maximum wave height) | |||
| Shiogama | Japan | 147 | 0.16 | Tide gauge (half the maximum wave height) | |||
| Ishinomaki | Japan | 151 | 0.15 | Tide gauge (half the maximum wave height) | day 5, 09:58 | ||
| Tsukihama | Japan | 164 | 0.32 | Tide gauge (half the maximum wave height) | day 5, 10:00 | ||
| Choshi | Japan | 167 | 0.14 | Tide gauge (half the maximum wave height) | day 5, 09:13 | ||
| Kesennumagyoko | Japan | 200 | 0.14 | Tide gauge (half the maximum wave height) | day 5, 09:23 | ||
| Miyako | Japan | 284 | 0.21 | Tide gauge (half the maximum wave height) | day 5, 09:53 | ||
| Hachinohe | Japan | 381 | 0.12 | Tide gauge (half the maximum wave height) | day 5, 10:13 | ||
| Hakodate | Japan | 520 | 0.05 | Tide gauge (half the maximum wave height) | day 5, 10:58 | ||
| Hakodateko | Japan | 527 | 0.03 | Tide gauge (half the maximum wave height) | |||
| Muroran | Japan | 586 | Tide gauge (half the maximum wave height) | ||||
| Kushiro | Japan | 691 | Tide gauge (half the maximum wave height) |
More
Every tsunami in 1938The 1900sTsunamis 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 1716.