November 30, 1938 Tsunami: Sanriku, Japan
A tsunami caused by a magnitude 7 earthquake began at Sanriku, Japan on November 30, 1938 at 02:29:00 UTC. The water rose as high as 0.2 meters. Its effects were recorded at 9 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
The tsunami
- Date
- November 30, 1938, 02:29:00 UTC
- Source
- Sanriku, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 7, 50 km deep
- Maximum water height
- 0.2 m (0.7 ft)
- Runups recorded
- 9
- Tsunami intensity (Soloviev-Imamura)
- -3
- Tsunami magnitude (Iida)
- -2.3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 37.000° N, 142.200° 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.
1938, November 30, 11:30 [local time]. There was an aftershock of the earthquake of November 5. It occurred in almost the same place as the shock of November 22. A weak tsunami was recorded on the coast of the Sanriku area and Hokkaido Island. The predominant period of oscillations on all the tide gauge records is 10-20 minutes. (reference #414)
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 | 116 | 0.08 | Tide gauge (half the maximum wave height) | day 30, 02:59 | ||
| Onagawa | Japan | 172 | 0.09 | Tide gauge (half the maximum wave height) | day 30, 02:59 | ||
| Ishinomaki | Japan | 177 | 0.05 | Tide gauge (half the maximum wave height) | day 30, 04:59 | ||
| Choshi | Japan | 183 | Tide gauge (half the maximum wave height) | day 30, 03:13 | |||
| Tsukihama | Japan | 186 | 0.06 | Tide gauge (half the maximum wave height) | day 30, 04:00 | ||
| Kesennumagyoko | Japan | 217 | 0.06 | Tide gauge (half the maximum wave height) | day 30, 03:32 | ||
| Hachinohe | Japan | 396 | 0.1 | Tide gauge (half the maximum wave height) | day 30, 06:04 | ||
| Hakodate | Japan | 539 | 0.05 | Tide gauge (half the maximum wave height) | day 30, 05:00 | ||
| Hakodateko | Japan | 546 | 0.08 | 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 1728.