Magnitude5.7

Reviewed by USGSPapua New Guinea55y ago

M5.7 earthquake 124 km SE of Kokopo, Papua New Guinea

Sunday, September 5, 1971, 03:00:13 UTC · 5.195°S, 153.006°E

A magnitude 5.7 earthquake struck 124 km SE of Kokopo, Papua New Guinea on Sunday, September 5, 1971, 03:00:13 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.0 on August 13, 1971.

Magnitude
5.7
Moderate · mw
Depth
35 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: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

5 kilotons of TNT

That is about 1/3 of the Hiroshima bomb. It released about 10 times the energy of a magnitude 5.0.

Tectonic setting

28 km

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

Depth: shallow

35 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 75 km

USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M5.3 on September 28, 1971. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M5.7
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.3126 km SSE of Kokopo, Papua New Guinea55y ago · 35 km SW of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 334 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 26 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 515 recorded deaths. The most severe:

  1. 1937

    Keravia, Rabaul, Kokopo

    28 May 1937 · 136 km away · intensity VIII

    507 deathsLimited damage (under $1M)tsunami

  2. 1941M7.4

    Bismarck Sea

    13 Jan 1941 · 154 km away

    4 deathsModerate damage ($1–5M)tsunami

  3. 1971M7.9

    New Ireland: Bougainville

    14 Jul 1971 · 105 km away · intensity IX

    3 deathsUnder $1 million damagetsunami

  4. 1878

    Bismarck Sea

    4 Feb 1878 · 134 km away

    1 deathtsunami

  5. 1967M6.4

    Bismarck Sea

    13 Aug 1967 · 105 km away

    Severe damage ($5–24M)tsunami

  6. 1971M8.1

    Bismarck Sea Rabaul

    26 Jul 1971 · 41 km away · intensity VI

    $1 million damagetsunami

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

Nearby trackers

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