Magnitude6.7

Reviewed by USGS47y ago

M6.7 earthquake south of the Fiji Islands

Sunday, April 13, 1980, 18:04:31 UTC · 23.466°S, 177.297°W

A magnitude 6.7 earthquake struck south of the Fiji Islands on Sunday, April 13, 1980, 18:04:31 UTC, at a depth of 79.0 km (intermediate). It is the strongest earthquake within 300 km since an M6.8 on June 22, 1977.

Magnitude
6.7
Strong · mb
Depth
79 km
Intermediate
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

169 kilotons of TNT

That is about 11 times the Hiroshima bomb. It released about 355 times the energy of a magnitude 5.0.

Tectonic setting

16 km

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

Depth: intermediate

79 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

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 3 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.5 on May 12, 1980. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M6.7
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.5south of the Fiji Islands47y ago · 21 km SE of this epicenter
  2. 5.3south of the Fiji Islands47y ago · 7 km SW of this epicenter
  3. 5.0south of the Fiji Islands47y ago · 71 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 375 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 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1 recorded deaths. The most severe:

  1. 1977M7.2

    Tonga Trench

    22 Jun 1977 · 157 km away · intensity IV

    1 death$1 million damagetsunami

  2. 1937M8.1

    Fiji Islands

    16 Apr 1937 · 221 km away

  3. 1975M7.8

    S Of Tonga

    11 Oct 1975 · 272 km away

  4. 1963M7.5

    Tonga Trench

    18 Dec 1963 · 164 km away

    tsunami

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

Nearby trackers

Closest city pages