M7.7 earthquake 120 km SW of Abepura, Indonesia

Sunday, January 10, 1971, 07:17:05 UTC · 3.212°S, 139.735°E

A magnitude 7.7 earthquake struck 120 km SW of Abepura, Indonesia on Sunday, January 10, 1971, 07:17:05 UTC, at a depth of 26.9 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on September 20, 1935.

Magnitude: 7.7; Major · mw
Depth: 27 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

5.4 megatons of TNT

That is about 355 times the Hiroshima bomb. It released about 11,220 times the energy of a magnitude 5.0.

Tectonic setting

9 km

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

Depth: shallow

27 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 17 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.6 on January 10, 1971. 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 84 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 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5 recorded deaths. The most severe:

1900M6.9
Nw. Irian Jaya
7 Oct 1900 · 92 km away
5 deathsLimited damage (under $1M)tsunami
1971M8.1
New Guinea: Irian Jaya:Djajapura,Sentani
10 Jan 1971 · 13 km away · intensity IX
Moderate damage ($1–5M)
1921
New Guinea: Irian Jaya: Sentani
10 Oct 1921 · 145 km away · intensity VII
Moderate damage ($1–5M)
1951M6.1
Bismarck Sea
22 Feb 1951 · 278 km away
Limited damage (under $1M)tsunami
1919
Irian Jaya Region
21 Nov 1919 · 135 km away · intensity VIII
Limited damage (under $1M)tsunami
1926M7.9
New Guinea: Irian Jaya
26 Oct 1926 · 141 km away

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

Nearby trackers