M7.8 earthquake 146 km SSE of Lata, Solomon Islands

Saturday, December 31, 1966, 18:23:09 UTC · 11.866°S, 166.473°E

A magnitude 7.8 earthquake struck 146 km SSE of Lata, Solomon Islands on Saturday, December 31, 1966, 18:23:09 UTC, at a depth of 59.0 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on December 17, 1957.

Magnitude: 7.8; Major · mw
Depth: 59 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

7.6 megatons of TNT

That is about 502 times the Hiroshima bomb. It released about 15,849 times the energy of a magnitude 5.0.

Tectonic setting

29 km

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

Depth: shallow

59 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 15 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M7.2 on December 31, 1966. 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 131 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 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1910M7.2
Espiritu Santo
10 Nov 1910 · 237 km away
Moderate damage ($1–5M)tsunami
1934M7.8
Santa Cruz Islands
18 Jul 1934 · 28 km away
tsunami
1957M7.8
Santa Cruz Islands
17 Dec 1957 · 54 km away
1966M7.8
Santa Cruz Islands
31 Dec 1966 · 4 km away
tsunami
1909M7.7
Solomon Islands
9 Dec 1909 · 263 km away
1900M7.6
Santa Cruz Islands
29 Jul 1900 · 263 km away

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

Nearby trackers