Reviewed by USGSWallis and Futuna71y ago
M7.6 earthquake 144 km SSW of Leava, Wallis and Futuna
Wednesday, May 23, 1956, 20:48:32 UTC · 15.434°S, 178.803°W
A magnitude 7.6 earthquake struck 144 km SSW of Leava, Wallis and Futuna on Wednesday, May 23, 1956, 20:48:32 UTC, at a depth of 419.1 km (deep). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.6
- Major · mw
- Depth
- 419 km
- Deep
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- IV
- Light (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
3.8 megatons of TNT
That is about 252 times the Hiroshima bomb. It released about 7,943 times the energy of a magnitude 5.0.
Tectonic setting
6 km
from the nearest mapped plate boundary, between the Futuna and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: deep
419 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 24 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.4227 km E of Levuka, FijiAugust 21, 1910 · 266 km S of this epicenter
- 7.1217 km E of Levuka, FijiJuly 8, 1916 · 290 km S of this epicenter
- 6.9130 km ENE of Labasa, FijiDecember 26, 1949 · 95 km SW of this epicenter
- 6.8Fiji regionSeptember 22, 1950 · 293 km SE of this epicenter
- 6.7179 km ENE of Levuka, FijiJune 21, 1928 · 213 km S of this epicenter
- 6.7139 km S of Alo, Wallis and FutunaJanuary 1, 1922 · 53 km E of this epicenter
- 6.584 km S of Alo, Wallis and FutunaMay 31, 1907 · 72 km NE of this epicenter
- 6.598 km NE of Labasa, FijiJuly 12, 1923 · 136 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1919M6.9
Rabi,Tunuloa Mission,Suvasavu
3 Oct 1919 · 167 km away · intensity VIII
Moderate damage ($1–5M)
- 1884
Macuata
Jan 1884 · 243 km away · intensity VII
Limited damage (under $1M)tsunami
- 1909M7.8
Fiji Islands
22 Feb 1909 · 286 km away
- 1956M7.5
Fiji Islands
23 May 1956 · 53 km away
- 1881
Fiji Islands
12 Jul 1881 · 243 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.