Reviewed by USGSPapua New Guinea51y ago
M5.0 earthquake 139 km SW of Panguna, Papua New Guinea
Saturday, September 27, 1975, 07:23:16 UTC · 7.316°S, 154.717°E
A magnitude 5.0 earthquake struck 139 km SW of Panguna, Papua New Guinea on Saturday, September 27, 1975, 07:23:16 UTC, at a depth of 41.0 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on September 25, 1975.
- Magnitude
- 5.0
- Moderate · mb
- Depth
- 41 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
477 tons of TNT
That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.
Tectonic setting
20 km
from the nearest mapped plate boundary, between the North Bismarck and Solomon Sea plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
41 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 2 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.2 on October 23, 1975. 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 422 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 · 295 km N of this epicenter
- 8.01971 New Britain EarthquakeJuly 14, 1971 · 226 km NW of this epicenter
- 7.956 km WSW of Panguna, Papua New GuineaJuly 20, 1975 · 89 km NE of this epicenter
- 7.885 km S of Panguna, Papua New GuineaJanuary 30, 1939 · 78 km E of this epicenter
- 7.794 km SSW of Panguna, Papua New GuineaJuly 20, 1975 · 53 km NE of this epicenter
- 7.7152 km SE of Kokopo, Papua New GuineaSeptember 29, 1946 · 280 km NW of this epicenter
- 7.5199 km SSE of Kokopo, Papua New GuineaAugust 17, 1972 · 245 km NW of this epicenter
- 7.3166 km SE of Kokopo, Papua New GuineaFebruary 12, 1968 · 261 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 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 · 78 km away
5 deathsModerate damage ($1–5M)tsunami
- 1971M7.9
New Ireland: Bougainville
14 Jul 1971 · 221 km away · intensity IX
3 deathsUnder $1 million damagetsunami
- 1975M7.9
Bismarck Sea: Bougainville
20 Jul 1975 · 89 km away · intensity VIII
Severe damage ($5–24M)tsunami
- 1959M7.3
Solomon Islands
17 Aug 1959 · 143 km away
Severe damage ($5–24M)tsunami
- 1974M7.1
Solomon Islands
1 Feb 1974 · 98 km away · intensity VI
Moderate damage ($1–5M)tsunami
- 1919M8.2
Solomon Islands
6 May 1919 · 295 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.