November 10, 1938 Tsunami: Shumagin Islands, AK, United States
A tsunami caused by a magnitude 8.2 earthquake began at Shumagin Islands, AK, United States on November 10, 1938 at 20:18:41 UTC. The water rose as high as 0.3 meters. Its effects were recorded at 9 places in at least 2 countries.
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
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
- November 10, 1938, 20:18:41 UTC
- Source
- Shumagin Islands, AK, United States
- Cause
- Earthquake
- Earthquake
- Magnitude 8.2, 25 km deep
- Maximum water height
- 0.3 m (1.0 ft)
- Runups recorded
- 9
- Tsunami magnitude (Iida)
- -1.7
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 55.480° N, 158.370° W
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 #542:
A magnitude 8.3 submarine earthquake, centered in a sparsely populated area near the Alaska Peninsula, generated a surprisingly small tsunami.
Reference #239:
It is conjectured that the tsunami was the result of submarine landslides or more likely to a very minor surface deformation associated with the earthquake.
Reference #414:
There was an earthquake with source near the Alaskan Peninsula. A tsunami occurred, and was recorded by at least six tide gauges. At remote stations, the tsunami apparently began with the flood tide.
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 |
|---|---|---|---|---|---|---|---|
| Unalaska, Dutch Harbor, AK, AK | United States | 554 | 0.1 | Tide gauge (half the maximum wave height) | day 10, 22:01 | ||
| Seward, AK, AK | United States | 740 | 0.08 | Tide gauge (half the maximum wave height) | day 10, 21:49 | ||
| Sitka, AK, AK | United States | 1,431 | 0.08 | Tide gauge (half the maximum wave height) | day 10, 22:42 | ||
| Tofino (Clayoquot),british Columbia, BC | Canada | 2,298 | 0.14 | Tide gauge (half the maximum wave height) | day 11, 00:11 | ||
| Crescent City, CA, CA | United States | 2,904 | 0.18 | Tide gauge (half the maximum wave height) | day 11, 00:32 | ||
| Honolulu, Oahu, HI, HI | United States | 3,794 | 0.1 | Tide gauge (half the maximum wave height) | day 11, 01:20 | ||
| Santa Monica, CA, CA | United States | 3,873 | 0.05 | Tide gauge (half the maximum wave height) | day 11, 01:20 | ||
| Hilo, Hawaii, HI, HI | United States | 3,978 | 0.3 | Tide gauge (half the maximum wave height) | |||
| San Diego, CA, CA | United States | 4,062 | 0.1 | Tide gauge (half the maximum wave height) | day 11, 03:11 |
More
Every tsunami in 1938The 1900sTsunamis of United StatesThe 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 1722.