Magnitude7.2

Reviewed by USGSPapua New Guinea55y ago

M7.2 earthquake 192 km NW of Panguna, Papua New Guinea

Friday, April 28, 1972, 23:32:10 UTC · 5.154°S, 154.188°E

A magnitude 7.2 earthquake struck 192 km NW of Panguna, Papua New Guinea on Friday, April 28, 1972, 23:32:10 UTC, at a depth of 403.3 km (deep). It is the strongest earthquake within 300 km since an M8.1 on July 26, 1971.

Magnitude
7.2
Major · mw
Depth
403 km
Deep
Felt reports
0
Did You Feel It?
Est. shaking
IV
Light (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

951 kilotons of TNT

That is about 63 times the Hiroshima bomb. It released about 1,995 times the energy of a magnitude 5.0.

Tectonic setting

65 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: deep

403 km

Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.

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 2 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.6 on April 29, 1972. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.2
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.6183 km ESE of Kokopo, Papua New Guinea55y ago · 51 km NW of this epicenter
  2. 5.654 km WSW of Panguna, Papua New Guinea55y ago · 182 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 327 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 520 recorded deaths. The most severe:

  1. 1937

    Keravia, Rabaul, Kokopo

    28 May 1937 · 241 km away · intensity VIII

    507 deathsLimited damage (under $1M)tsunami

  2. 1939M7.7

    Bougainville Island

    30 Jan 1939 · 252 km away

    5 deathsModerate damage ($1–5M)tsunami

  3. 1941M7.4

    Bismarck Sea

    13 Jan 1941 · 259 km away

    4 deathsModerate damage ($1–5M)tsunami

  4. 1971M7.9

    New Ireland: Bougainville

    14 Jul 1971 · 50 km away · intensity IX

    3 deathsUnder $1 million damagetsunami

  5. 1878

    Bismarck Sea

    4 Feb 1878 · 237 km away

    1 deathtsunami

  6. 1967M6.4

    Bismarck Sea

    13 Aug 1967 · 205 km away

    Severe damage ($5–24M)tsunami

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

Nearby trackers

Closest city pages