Reviewed by USGSPapua New Guinea29y ago
M4.1 earthquake eastern New Guinea region, Papua New Guinea
Saturday, February 21, 1998, 19:00:38 UTC · 5.931°S, 146.174°E
A magnitude 4.1 earthquake struck eastern New Guinea region, Papua New Guinea on Saturday, February 21, 1998, 19:00:38 UTC, at a depth of 100.0 km (intermediate).
- Magnitude
- 4.1
- Light · mb
- Depth
- 100 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
27 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
100 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 50 km
USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M3.7 on March 10, 1998. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 829 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.01906 Papua New Guinea EarthquakeSeptember 14, 1906 · 121 km E of this epicenter
- 7.638 km NW of Finschhafen, Papua New GuineaOctober 2, 1906 · 162 km E of this epicenter
- 7.548 km NW of Finschhafen, Papua New GuineaMay 12, 1938 · 157 km E of this epicenter
- 7.549 km WSW of Wau, Papua New GuineaFebruary 26, 1963 · 178 km S of this epicenter
- 7.492 km WSW of Kandrian, Papua New GuineaMay 6, 1947 · 292 km E of this epicenter
- 7.454 km NNW of Finschhafen, Papua New GuineaFebruary 8, 1987 · 168 km E of this epicenter
- 7.2117 km N of Finschhafen, Papua New GuineaDecember 22, 1997 · 193 km E of this epicenter
- 7.261 km NNW of Finschhafen, Papua New GuineaMay 15, 1992 · 155 km E of this epicenter
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 155 recorded deaths. The most severe:
- 1988M4.3
Kaiapit (Landslide Generated)
6 Sep 1988 · 16 km away
74 deathsModerate damage ($1–5M)
- 1993M6.9
Eastern: Upper Markham Valley
13 Oct 1993 · 18 km away
60 deaths$5 million damage
- 1970M7.3
Madang
31 Oct 1970 · 138 km away · intensity VIII
18 deaths$2 million damagetsunami
- 1987M7.6
Huon Peninsula, Umboi Island
8 Feb 1987 · 168 km away · intensity VII
3 deaths$3 million damagetsunami
- 1857M8.0
Bismarck Sea
17 Apr 1857 · 103 km away
Moderate damage ($1–5M)tsunami
- 1873M8.0
Maclay Coast
1873 · 52 km away · intensity IX
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.