April 27, 1975 Tsunami: Kitimat Inlet, British Columbia, Canada
A tsunami caused by a landslide began at Kitimat Inlet, British Columbia, Canada on April 27, 1975 at 18:05 UTC. The water rose as high as 4.1 meters. Its effects were recorded at 5 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
- April 27, 1975, 18:05 UTC
- Source
- Kitimat Inlet, British Columbia, Canada
- Cause
- Landslide
- Maximum water height
- 4.1 m (13.5 ft)
- Runups recorded
- 5
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 53.980° N, 128.680° W
The toll
- Damage
- Moderate (about $1 to $5 million)
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.
At 10:05 A.M. (LT) on April 27, 1975, a major submarine slope failure occurred at the head of Kitimat Inlet on the coast of British Columbia (53 deg 59 min N, 128 deg 41 min W). Resulting downslope movement of a large volume of sediment in the vicinity of the Kitimat delta caused substantial demage to nearby dock facilities and coastal settlements.
On January 1975, construction was completed on a 7.5 m-high rock fill crib wharf built outward from the beach at Moon Bay. On April 1975, construction of a rock fill and dredged sand breakwater was initiated using coarse dredge material excavated from the bottom within and slightly seaward of the tidal zone. On the morning of April 27, 1975, the breakwater and crib wharf were seen to move seaward, being carried by the initial movement of the sediment slide, approximately 53 minutes after extreme low
tide (6.02 m drawdown from high tide). On April 27, 1975, following a major slide, water waves with ranged up to 8.2 m were generated...
The slump originated across a front approximately 1 km wide and travelled approximately 5 km down the inlet to a final water depth of 210 m. The main part of this path was over ~ 1/2 deg slopes. The associated water wave amplitude, possible as large as 8 m and water disturbance for about 1 hour was responsible for the destruction of boats, docks and other property.
At the time of occurrence of the slide of April 27At the time of occurrence of the slide of April 27, 1975, there was no mujor seismic event reported in that area. Also, there was no meteorological event at that time which could have caused large water level oscillations. Hence, there is no doubt that the water waves were generated by the submarine slide. At least two water waves (and possibly three) were generated, and propagated into the connecting bays and channels, The largest wave was estimated to be 8.2 m in range (crest to through)... The whole water-level disturbance lasted about an hour. In Bish Creek and Clio Bay, which are about 8 km from the site of the slide, at least one wave was observed.
(above from reference #4153)
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 |
|---|---|---|---|---|---|---|---|
| Bish Creek, British Columbia, BC | Canada | 0 | Eyewitness observation of water height | ||||
| Clio Bay, British Columbia, BC | Canada | 9 | 3.35 | Eyewitness observation of water height | |||
| Kildala Arm, British Columbia, BC | Canada | 16 | Eyewitness observation of water height | ||||
| Kitimat Arm, British Columbia, BC | Canada | 51 | 4.1 | Eyewitness observation of water height | day 27, 18:05 | ||
| Moon Cove, British Columbia, BC | Canada | Eyewitness observation of water height |
More
Every tsunami in 1975The 1900sTsunamis of CanadaThis 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 2879.