May 20, 1987 Tsunami: Deep Cove, New Zealand
A tsunami caused by a landslide began at Deep Cove, New Zealand on May 20, 1987. 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
- May 20, 1987
- Source
- Deep Cove, New Zealand
- Cause
- Landslide
- Runups recorded
- 1
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 45.460° S, 167.150° E
The toll
- Damage
- Limited (under about $1 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.
Reference #5324:
1987, May 20. A large landslide into Deep Cove created a wave that lifted a 17 m launch onto its wharf. The landslide was about 400 m high and 50-60 m wide, and fell straight outwards from the north face of fiord. A 2-3 m wall of water lifted the launch on to its 10 m [long?] wharf, demolishing it. The boat suffered some damage as well as other boats nearby in the cove. The slip was note triggered by an earthquake.
On 20 May 1987, a large landslide, with dimensions, 400 m (height) x 50-60 m (width) x unspecified depth, was observed to fall straight outwards from the north face of the fiord into Deep Cove, Doubtful Sound, opposite the main wharf, causing a 2-3 m “wall of water”.(Southland Times, 1987 May 23). This swept a 17 m launch onto a 10 m long wharf, demolishing it. There was minor damage to the launch, and to other boats. The landslide occurred in calm conditions with no obvious triggers, such as storm or earthquake.
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 |
|---|---|---|---|---|---|---|---|
| Deep Cove: Wanganella Cove | New Zealand | 0 | Eyewitness observation of water height |
More
Every tsunami in 1987The 1900sTsunamis of New ZealandThis 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 5514.