Reviewed by USGSPapua New Guinea53y ago
M4.6 earthquake 102 km SW of Panguna, Papua New Guinea
Thursday, February 28, 1974, 00:07:56 UTC · 6.963°S, 154.825°E
A magnitude 4.6 earthquake struck 102 km SW of Panguna, Papua New Guinea on Thursday, February 28, 1974, 00:07:56 UTC, at a depth of 46.0 km (shallow). It is the strongest earthquake within 300 km since an M5.1 on February 27, 1974.
- Magnitude
- 4.6
- Light · mb
- Depth
- 46 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
5 km
from the nearest mapped plate boundary, between the Pacific and North Bismarck plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
46 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 50 km
USGS lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.6 on March 13, 1974. 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 301 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.21919 Papua New Guinea EarthquakeMay 6, 1919 · 263 km NW of this epicenter
- 8.11971 Bougainville EarthquakeJuly 26, 1971 · 295 km NW of this epicenter
- 8.01971 New Britain EarthquakeJuly 14, 1971 · 197 km NW of this epicenter
- 7.885 km S of Panguna, Papua New GuineaJanuary 30, 1939 · 64 km E of this epicenter
- 7.7152 km SE of Kokopo, Papua New GuineaSeptember 29, 1946 · 255 km NW of this epicenter
- 7.5199 km SSE of Kokopo, Papua New GuineaAugust 17, 1972 · 235 km NW of this epicenter
- 7.3166 km SE of Kokopo, Papua New GuineaFebruary 12, 1968 · 239 km NW of this epicenter
- 7.361 km NW of Gizo, Solomon IslandsApril 19, 1936 · 201 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 8 recorded deaths. The most severe:
- 1939M7.7
Bougainville Island
30 Jan 1939 · 63 km away
5 deathsModerate damage ($1–5M)tsunami
- 1971M7.9
New Ireland: Bougainville
14 Jul 1971 · 192 km away · intensity IX
3 deathsUnder $1 million damagetsunami
- 1959M7.3
Solomon Islands
17 Aug 1959 · 143 km away
Severe damage ($5–24M)tsunami
- 1971M8.1
Bismarck Sea Rabaul
26 Jul 1971 · 295 km away · intensity VI
$1 million damagetsunami
- 1974M7.1
Solomon Islands
1 Feb 1974 · 98 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1919M8.2
Solomon Islands
6 May 1919 · 263 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.