M6.1 earthquake 125 km NE of Finschhafen, Papua New Guinea

Tuesday, May 18, 1999, 04:19:53 UTC · 5.650°S, 148.533°E

A magnitude 6.1 earthquake struck 125 km NE of Finschhafen, Papua New Guinea on Tuesday, May 18, 1999, 04:19:53 UTC, at a depth of 127.3 km (intermediate). It is the strongest earthquake within 300 km since an M7.1 on May 10, 1999.

Magnitude: 6.1; Strong · mwc
Depth: 127 km; Intermediate
Felt reports: 0; Did You Feel It?
Est. shaking: IV; Light (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

21 kilotons of TNT

That is about the energy of the Hiroshima bomb. It released about 45 times the energy of a magnitude 5.0.

Tectonic setting

175 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

127 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 100 km

USGS lists 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M4.9 on June 9, 1999. 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 992 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 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 138 recorded deaths. The most severe:

1988M4.3
Kaiapit (Landslide Generated)
6 Sep 1988 · 259 km away
74 deathsModerate damage ($1–5M)
1993M6.9
Eastern: Upper Markham Valley
13 Oct 1993 · 279 km away
60 deaths$5 million damage
1987M7.6
Huon Peninsula, Umboi Island
8 Feb 1987 · 105 km away · intensity VII
3 deaths$3 million damagetsunami
1985M7.1
New Britain: Bialla, Piona
10 May 1985 · 278 km away · intensity VIII
1 death$1 million damage
1906M8.0
New Britain
14 Sep 1906 · 159 km away
Severe damage ($5–24M)tsunami
1857M8.0
Bismarck Sea
17 Apr 1857 · 170 km away
Moderate damage ($1–5M)tsunami

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

Nearby trackers