Reviewed by USGSPapua New Guinea49y ago
M5.9 earthquake 57 km WSW of Panguna, Papua New Guinea
Friday, August 12, 1977, 00:07:51 UTC · 6.533°S, 155.011°E
A magnitude 5.9 earthquake struck 57 km WSW of Panguna, Papua New Guinea on Friday, August 12, 1977, 00:07:51 UTC, at a depth of 58.0 km (shallow). It is the strongest earthquake within 300 km since an M7.2 on July 29, 1977.
- Magnitude
- 5.9
- Moderate · mb
- Depth
- 58 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
11 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 22 times the energy of a magnitude 5.0.
Tectonic setting
43 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
58 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 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M4.4 on September 6, 1977. 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 554 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 · 230 km NW of this epicenter
- 8.11971 Bougainville EarthquakeJuly 26, 1971 · 274 km NW of this epicenter
- 8.01971 New Britain EarthquakeJuly 14, 1971 · 174 km NW of this epicenter
- 7.956 km WSW of Panguna, Papua New GuineaJuly 20, 1975 · 8 km SE of this epicenter
- 7.885 km S of Panguna, Papua New GuineaJanuary 30, 1939 · 74 km SE of this epicenter
- 7.794 km SSW of Panguna, Papua New GuineaJuly 20, 1975 · 65 km S of this epicenter
- 7.7152 km SE of Kokopo, Papua New GuineaSeptember 29, 1946 · 237 km NW of this epicenter
- 7.5199 km SSE of Kokopo, Papua New GuineaAugust 17, 1972 · 239 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 19 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 · 74 km away
5 deathsModerate damage ($1–5M)tsunami
- 1971M7.9
New Ireland: Bougainville
14 Jul 1971 · 168 km away · intensity IX
3 deathsUnder $1 million damagetsunami
- 1975M7.9
Bismarck Sea: Bougainville
20 Jul 1975 · 8 km away · intensity VIII
Severe damage ($5–24M)tsunami
- 1959M7.3
Solomon Islands
17 Aug 1959 · 153 km away
Severe damage ($5–24M)tsunami
- 1971M8.1
Bismarck Sea Rabaul
26 Jul 1971 · 274 km away · intensity VI
$1 million damagetsunami
- 1974M7.1
Solomon Islands
1 Feb 1974 · 116 km away · intensity VI
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.