M5.0 earthquake 108 km ESE of Madang, Papua New Guinea

Tuesday, August 25, 1992, 06:58:39 UTC · 5.523°S, 146.717°E

A magnitude 5.0 earthquake struck 108 km ESE of Madang, Papua New Guinea on Tuesday, August 25, 1992, 06:58:39 UTC, at a depth of 235.9 km (intermediate). It is the strongest earthquake within 300 km since an M6.3 on August 16, 1992.

Magnitude: 5.0; Moderate · mb
Depth: 236 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 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

100 km

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

Depth: intermediate

236 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 75 km

USGS lists 6 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.6 on August 29, 1992. 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 733 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 20 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 95 recorded deaths. The most severe:

1988M4.3
Kaiapit (Landslide Generated)
6 Sep 1988 · 80 km away
74 deathsModerate damage ($1–5M)
1970M7.3
Madang
31 Oct 1970 · 154 km away · intensity VIII
18 deaths$2 million damagetsunami
1987M7.6
Huon Peninsula, Umboi Island
8 Feb 1987 · 125 km away · intensity VII
3 deaths$3 million damagetsunami
1857M8.0
Bismarck Sea
17 Apr 1857 · 31 km away
Moderate damage ($1–5M)tsunami
1873M8.0
Maclay Coast
1873 · 79 km away · intensity IX
Moderate damage ($1–5M)tsunami
1987M7.7
New Britain: Kandrian, Kimbte
16 Oct 1987 · 272 km away · intensity VIII
Moderate damage ($1–5M)tsunami

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

Nearby trackers