Magnitude4.9

Reviewed by USGSPapua New Guinea35y ago

M4.9 earthquake 127 km SW of Kokopo, Papua New Guinea

Thursday, May 2, 1991, 17:41:31 UTC · 5.105°S, 151.408°E

A magnitude 4.9 earthquake struck 127 km SW of Kokopo, Papua New Guinea on Thursday, May 2, 1991, 17:41:31 UTC, at a depth of 154.4 km (intermediate). It is the strongest earthquake within 300 km since an M5.8 on April 11, 1991.

Magnitude
4.9
Light · mb
Depth
154 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 earthquake

In context

How big was it, and why here?

Energy released

338 tons of TNT

That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.

Tectonic setting

105 km

from the nearest mapped plate boundary, between the South Bismarck and Solomon Sea plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: intermediate

154 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 50 km

USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,060 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 36 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 527 recorded deaths. The most severe:

  1. 1937

    Keravia, Rabaul, Kokopo

    28 May 1937 · 128 km away · intensity VIII

    507 deathsLimited damage (under $1M)tsunami

  2. 1983M6.4

    Ulawun, Rabaul

    22 Dec 1983 · 60 km away · intensity V

    10 deaths$25 million damage

  3. 1941M7.4

    Bismarck Sea

    13 Jan 1941 · 127 km away

    4 deathsModerate damage ($1–5M)tsunami

  4. 1971M7.9

    New Ireland: Bougainville

    14 Jul 1971 · 279 km away · intensity IX

    3 deathsUnder $1 million damagetsunami

  5. 1985M7.1

    New Britain: Bialla, Piona

    10 May 1985 · 68 km away · intensity VIII

    1 death$1 million damage

  6. 1989M5.4

    New Britain: Rabaul

    10 Mar 1989 · 176 km away · intensity V

    1 death

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

Nearby trackers

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