July 16, 1865 Tsunami: Unalaska Island, AK, United States
A tsunami caused by an earthquake began at Unalaska Island, AK, United States on July 16, 1865 at 03:00:00 UTC. Its effects were recorded at 1 place.
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
- July 16, 1865, 03:00:00 UTC
- Source
- Unalaska Island, AK, United States
- Cause
- Earthquake
- Runups recorded
- 1
- Waters
- Ocean
- How certain
- Very doubtful tsunami
- Source location
- 54.000° N, 167.000° W
The toll
- Damage
- Limited (under about $1 million)
- Houses destroyed
- Few (about 1 to 50)
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.
This major earthquake continued for five minutes, collapsing cliffs and causing the settlement of Unalaska to be inundated by water as a result of subsidence. Reports do not suggest that this inundation represented the occurrence of a tsunami. (Ref #239)
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, AK, AK doubtful | United States | 0 | Eyewitness observation of water height | day 16, 03:00 |
More
Every tsunami in 1865The 1800sTsunamis of United StatesThis 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 938.