Magnitude4.4

Reviewed by USGSPapua New Guinea41y ago

M4.4 earthquake 72 km S of Kokopo, Papua New Guinea

Wednesday, June 26, 1985, 15:39:10 UTC · 4.991°S, 152.143°E

A magnitude 4.4 earthquake struck 72 km S of Kokopo, Papua New Guinea on Wednesday, June 26, 1985, 15:39:10 UTC, at a depth of 362.1 km (deep).

Magnitude
4.4
Light · mb
Depth
362 km
Deep
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: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

60 tons of TNT

That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.

Tectonic setting

84 km

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

Depth: deep

362 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 50 km

USGS lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on July 1, 1985. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M41h6h1d3d7d14d30dMainshock M4.4
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 3.690 km SSW of Kokopo, Papua New Guinea41y ago · 25 km SW of this epicenter
  2. 3.944 km SSE of Kokopo, Papua New Guinea41y ago · 46 km NE of this epicenter
  3. 4.685 km S of Kokopo, Papua New Guinea41y ago · 23 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 867 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 33 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 526 recorded deaths. The most severe:

  1. 1937

    Keravia, Rabaul, Kokopo

    28 May 1937 · 80 km away · intensity VIII

    507 deathsLimited damage (under $1M)tsunami

  2. 1983M6.4

    Ulawun, Rabaul

    22 Dec 1983 · 54 km away · intensity V

    10 deaths$25 million damage

  3. 1941M7.4

    Bismarck Sea

    13 Jan 1941 · 91 km away

    4 deathsModerate damage ($1–5M)tsunami

  4. 1971M7.9

    New Ireland: Bougainville

    14 Jul 1971 · 203 km away · intensity IX

    3 deathsUnder $1 million damagetsunami

  5. 1985M7.1

    New Britain: Bialla, Piona

    10 May 1985 · 139 km away · intensity VIII

    1 death$1 million damage

  6. 1878

    Bismarck Sea

    4 Feb 1878 · 83 km away

    1 deathtsunami

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

Nearby trackers

Closest city pages