M6.0 earthquake 278 km ESE of Tadine, New Caledonia

Monday, September 21, 1981, 14:24:42 UTC · 22.185°S, 170.491°E

A magnitude 6.0 earthquake struck 278 km ESE of Tadine, New Caledonia on Monday, September 21, 1981, 14:24:42 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M6.6 on September 17, 1981.

Magnitude: 6.0; Strong · ms
Depth: 33 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: —; No ShakeMap
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

15 kilotons of TNT

That is about the energy of the Hiroshima bomb. It released about 32 times the energy of a magnitude 5.0.

Tectonic setting

58 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

33 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 100 km

USGS lists 6 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.0 on September 30, 1981. 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 394 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 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1901M7.9
Loyalty Islands
9 Aug 1901 · 55 km away
Moderate damage ($1–5M)tsunami
1910M7.5
Vanuatu Islands
1 Jun 1910 · 288 km away
1928M7.5
Loyalty Islands
16 Mar 1928 · 21 km away
1943M7.5
Loyalty Islands
14 Sep 1943 · 56 km away
1944M7.5
Loyalty Islands
5 Oct 1944 · 159 km away
1972M7.0
Loyalty Islands: Tanna, Anatom
2 Nov 1972 · 300 km away · intensity V

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

Nearby trackers