Magnitude5.0

Reviewed by USGSPapua New Guinea50y ago

M5.0 earthquake 112 km WNW of Panguna, Papua New Guinea

Sunday, July 25, 1976, 10:02:46 UTC · 5.892°S, 154.565°E

A magnitude 5.0 earthquake struck 112 km WNW of Panguna, Papua New Guinea on Sunday, July 25, 1976, 10:02:46 UTC, at a depth of 52.0 km (shallow). It is the strongest earthquake within 300 km since an M5.3 on July 21, 1976.

Magnitude
5.0
Moderate · mb
Depth
52 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

477 tons of TNT

That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.

Tectonic setting

3 km

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

Depth: shallow

52 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 2 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.8 on August 11, 1976. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M5.0
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.8131 km WNW of Panguna, Papua New Guinea50y ago · 33 km SW of this epicenter
  2. 4.7129 km WNW of Panguna, Papua New Guinea50y ago · 24 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 595 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 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 8 recorded deaths. The most severe:

  1. 1939M7.7

    Bougainville Island

    30 Jan 1939 · 160 km away

    5 deathsModerate damage ($1–5M)tsunami

  2. 1971M7.9

    New Ireland: Bougainville

    14 Jul 1971 · 86 km away · intensity IX

    3 deathsUnder $1 million damagetsunami

  3. 1975M7.9

    Bismarck Sea: Bougainville

    20 Jul 1975 · 95 km away · intensity VIII

    Severe damage ($5–24M)tsunami

  4. 1959M7.3

    Solomon Islands

    17 Aug 1959 · 239 km away

    Severe damage ($5–24M)tsunami

  5. 1967M6.4

    Bismarck Sea

    13 Aug 1967 · 283 km away

    Severe damage ($5–24M)tsunami

  6. 1971M8.1

    Bismarck Sea Rabaul

    26 Jul 1971 · 191 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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