M5.1 earthquake 38 km N of Finschhafen, Papua New Guinea

Wednesday, May 13, 1987, 21:27:07 UTC · 6.208°S, 147.830°E

A magnitude 5.1 earthquake struck 38 km N of Finschhafen, Papua New Guinea on Wednesday, May 13, 1987, 21:27:07 UTC, at a depth of 48.3 km (shallow). It is the strongest earthquake within 300 km since an M5.3 on April 11, 1987.

Magnitude: 5.1; Moderate · mb
Depth: 48 km; Shallow
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

674 tons of TNT

That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.

Tectonic setting

102 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: shallow

48 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

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 9 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.0 on June 7, 1987. 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 538 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 21 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 21 recorded deaths. The most severe:

1970M7.3
Madang
31 Oct 1970 · 298 km away · intensity VIII
18 deaths$2 million damagetsunami
1987M7.6
Huon Peninsula, Umboi Island
8 Feb 1987 · 21 km away · intensity VII
3 deaths$3 million damagetsunami
1906M8.0
New Britain
14 Sep 1906 · 156 km away
Severe damage ($5–24M)tsunami
1857M8.0
Bismarck Sea
17 Apr 1857 · 121 km away
Moderate damage ($1–5M)tsunami
1873M8.0
Maclay Coast
1873 · 217 km away · intensity IX
Moderate damage ($1–5M)tsunami
1987M7.7
New Britain: Kandrian, Kimbte
16 Oct 1987 · 136 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