December 6, 1917 Tsunami: Halifax, Nova Scotia, Canada
A tsunami caused by an explosion began at Halifax, Nova Scotia, Canada on December 6, 1917 at 13:04 UTC. The water rose as high as 7 meters. Its effects were recorded at 5 places. It killed 2,000 people, 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
- December 6, 1917, 13:04 UTC
- Source
- Halifax, Nova Scotia, Canada
- Cause
- Explosion
- Maximum water height
- 7 m (23.0 ft)
- Runups recorded
- 5
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 44.633° N, 63.583° W
The toll
- Deaths
- Some (about 51 to 100); 2,000 with the earthquake or eruption that caused it
- Injuries
- 9,000 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.
9:04 a.m., local time, based on seismograph at Dalhousie University. The munitions ship Mont Blanc collided with the relief ship Imo in the Narrows of Halifax Harbour. The Mont Blanc was carrying about 2,630 tons of TNT. A fire broke out on the Mont Blanc, and the ship drifted onto the Halifax side of the harbor. The cargo exploded, devastating a large section of the city. Almost 2000 people were killed and 9000 injured; some deaths are attributed to the tsunami that followed the explosion.
There were no operational tide gauges, but survivors reported large waves and extreme water levels. Model results show that the waves may have been as high as 10 m at the explosion site, but that the tsunami diminished away from the source (reference #2039).
Although the tsunami was clearly a factor in some deaths and swept some bodies of the dead back into the Narrows, the occasionally cited figure of 200 tsunami victims is significantly overstated; in truth, the number of tsunami caused deaths can never be known because autopsies were not done on the explosion's 2,000 victims. (reference #2401)
Jones (reference #2040) in his survey of Canadian disasters, does not include this as a tsunami event. Clague et al. (reference #1400) includes this as a tsunami produced by an explosion. This event has been debated by tsunami researchers for many years.
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 |
|---|---|---|---|---|---|---|---|
| Halifax, Nova Scotia, NS | Canada | 0 | 7 | Eyewitness observation of water height | |||
| Dartmouth, Nova Scotia, NS | Canada | 4 | Eyewitness observation of water height | day 6, 13:06 | |||
| Tufts Cove, Nova Scotia, NS | Canada | 5 | Eyewitness observation of water height | day 6, 13:06 | 9 | ||
| Turtle Grove, Nova Scotia, NS | Canada | 5 | Eyewitness observation of water height | day 6, 13:06 | 7 | ||
| Bedford, Nova Scotia, NS | Canada | 12 | Eyewitness observation of water height | day 6, 13:12 |
More
Every tsunami in 1917The 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 2792.