July 25, 1979 Tsunami: Mururoa Atoll, French Polynesia

Name: July 25, 1979 Tsunami: Mururoa Atoll, French Polynesia
Start: 1979-07-25
Location: Mururoa Atoll, French Polynesia

July 25, 1979 · 1.5 m · Probable tsunami

A tsunami caused by a landslide began at Mururoa Atoll, French Polynesia on July 25, 1979. The water rose as high as 1.5 meters. Its effects were recorded at 2 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

Tsunami warnings in force

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: July 25, 1979
Source: Mururoa Atoll, French Polynesia
Cause: Landslide
Maximum water height: 1.5 m (4.9 ft)
Runups recorded: 2
Waters: Ocean
How certain: Probable tsunami
Source location: 21.870° S, 138.910° W

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.

A landslide-generated tsunami was observed in 1979 along the south coasts of Mururoa as well as on Fangataufa atoll located 40 km south of Mururoa. The atoll of Mururoa is characterized by amean slope of 60 deg in the water depth range (0–500 m). This latter slope decreases progressively from 500 to 4000 m. The 1979 landslide occurred on the 60 deg mean slope and may be associated to destabilizations of oceanic island flanks with large velocities and initial accelerations. (reference #14395)

probable volume of the immediate rockslide: 110 million m3. height of the wave on the motus 2.5m at the epicenter, 90 s after the rockslide.

This landslide was generated by an explosion of a nuclear device on 25 July 1979.

Note: observations in near-field from airborne imagery; before reaching shore waves reached 5-6 m on reef flat and 1.5-2m before entering lagoon. On a neighboring atoll eyewitness, observed a 1.5 m wave above sea level.

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
Mururoa Atoll	French Polynesia	6			Water height, post-tsunami survey
Fangataufa Atoll	French Polynesia	41	1.5		Eyewitness observation of water height

Every tsunami in 1979 The 1900s Tsunamis of French Polynesia This day in weather history Alerts 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 6175.