M7.2 earthquake 44 km SSW of Angoram, Papua New Guinea

Tuesday, June 24, 1986, 03:11:30 UTC · 4.448°S, 143.943°E

A magnitude 7.2 earthquake struck 44 km SSW of Angoram, Papua New Guinea on Tuesday, June 24, 1986, 03:11:30 UTC, at a depth of 102.3 km (intermediate). It is the strongest earthquake within 300 km since an M7.8 on September 20, 1935.

Magnitude: 7.2; Major · mw
Depth: 102 km; Intermediate
Felt reports: 0; Did You Feel It?
Est. shaking: VII; Very strong (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

68 km

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

Depth: intermediate

102 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 200 km

USGS lists 12 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.3 on July 6, 1986. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 286 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 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 18 recorded deaths. The most severe:

1970M7.3
Madang
31 Oct 1970 · 177 km away · intensity VIII
18 deaths$2 million damagetsunami
1873M8.0
Maclay Coast
1873 · 256 km away · intensity IX
Moderate damage ($1–5M)tsunami
1968M7.5
N Coast, Wewak, Dagua
23 Oct 1968 · 137 km away
Moderate damage ($1–5M)
1907M7.4
Bismarck Sea
15 Dec 1907 · 219 km away
Moderate damage ($1–5M)tsunami
1984M6.6
Karkar
27 Mar 1984 · 208 km away · intensity VIII
Moderate damage ($1–5M)
1979M6.2
E, Mt Hagen
25 Jun 1979 · 190 km away
Moderate damage ($1–5M)

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

Nearby trackers