M7.6 earthquake 31 km S of Luganville, Vanuatu

Wednesday, August 11, 1965, 22:31:52 UTC · 15.804°S, 167.180°E

A magnitude 7.6 earthquake struck 31 km S of Luganville, Vanuatu on Wednesday, August 11, 1965, 22:31:52 UTC, at a depth of 47.6 km (shallow). It is the strongest earthquake within 300 km since an M7.7 on May 20, 1965.

Magnitude: 7.6; Major · mw
Depth: 48 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VII; Very strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured 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

89 km

from the nearest mapped plate boundary, between the New Hebrides and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

48 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

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 lists 12 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M7.4 on August 13, 1965. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 136 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1965M7.6
Vanuatu Islands
11 Aug 1965 · 2 km away
Moderate damage ($1–5M)tsunami
1910M7.2
Espiritu Santo
10 Nov 1910 · 213 km away
Moderate damage ($1–5M)tsunami
1909
Espiritu Santo
8 Jul 1909 · 34 km away
Moderate damage ($1–5M)tsunami
1965M7.4
Vanuatu Islands
13 Aug 1965 · 42 km away
Limited damage (under $1M)tsunami
1933M6.4
Malekula
19 Nov 1933 · 137 km away
Limited damage (under $1M)tsunami
1903M7.9
Vanuatu Islands
13 May 1903 · 159 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers