Reviewed by USGSPapua New Guinea81y ago
M7.7 earthquake 152 km SE of Kokopo, Papua New Guinea
Sunday, September 29, 1946, 03:02:06 UTC · 5.204°S, 153.340°E
A magnitude 7.7 earthquake struck 152 km SE of Kokopo, Papua New Guinea on Sunday, September 29, 1946, 03:02:06 UTC, at a depth of 50.0 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on February 2, 1920.
- Magnitude
- 7.7
- Major · mw
- Depth
- 50 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
5.0 megatons of TNT
That is about 332 times the Hiroshima bomb. It released about 10,471 times the energy of a magnitude 5.0.
Tectonic setting
3 km
from the nearest mapped plate boundary, between the North Bismarck and South Bismarck plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
50 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 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 108 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 · 73 km NE of this epicenter
- 8.060 km SE of Kokopo, Papua New GuineaJanuary 1, 1916 · 93 km NW of this epicenter
- 7.874 km SSW of Kokopo, Papua New GuineaFebruary 2, 1920 · 149 km W of this epicenter
- 7.497 km SW of Rabaul, Papua New GuineaMay 30, 1913 · 208 km W of this epicenter
- 7.2New Britain region, Papua New GuineaJanuary 13, 1941 · 188 km NW of this epicenter
- 7.2205 km SE of Kokopo, Papua New GuineaDecember 23, 1943 · 54 km SE of this epicenter
- 7.196 km ESE of Kokopo, Papua New GuineaMay 3, 1946 · 70 km NW of this epicenter
- 7.061 km ENE of Kimbe, Papua New GuineaFebruary 28, 1934 · 298 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 512 recorded deaths. The most severe:
- 1937
Keravia, Rabaul, Kokopo
28 May 1937 · 163 km away · intensity VIII
507 deathsLimited damage (under $1M)tsunami
- 1941M7.4
Bismarck Sea
13 Jan 1941 · 181 km away
4 deathsModerate damage ($1–5M)tsunami
- 1878
Bismarck Sea
4 Feb 1878 · 161 km away
1 deathtsunami
- 1899
New Ireland: East Coast
15 Jan 1899 · 287 km away
Moderate damage ($1–5M)tsunami
- 1919M8.2
Solomon Islands
6 May 1919 · 73 km away
Limited damage (under $1M)tsunami
- 1916M7.9
Solomon Islands
1 Jan 1916 · 102 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.