Reviewed by USGSPapua New Guinea40y ago
M4.3 earthquake 135 km ENE of Angoram, Papua New Guinea
Friday, July 4, 1986, 22:18:52 UTC · 3.532°S, 145.163°E
A magnitude 4.3 earthquake struck 135 km ENE of Angoram, Papua New Guinea on Friday, July 4, 1986, 22:18:52 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 10 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 earthquake
In context
How big was it, and why here?
Energy released
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
2 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
10 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
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:
- 7.650 km N of Wewak, Papua New GuineaJuly 3, 1918 · 183 km W of this epicenter
- 7.349 km NNE of Angoram, Papua New GuineaMay 7, 1907 · 103 km W of this epicenter
- 7.244 km SSW of Angoram, Papua New GuineaJune 24, 1986 · 169 km SW of this epicenter
- 7.1132 km NNE of Wewak, Papua New GuineaAugust 26, 1906 · 159 km NW of this epicenter
- 7.165 km ENE of Wewak, Papua New GuineaApril 27, 1909 · 113 km W of this epicenter
- 7.061 km W of Angoram, Papua New GuineaJune 9, 1925 · 194 km W of this epicenter
- 7.055 km NNW of Ambunti, Papua New GuineaSeptember 20, 1935 · 281 km W of this epicenter
- 7.042 km WNW of Wewak, Papua New GuineaOctober 23, 1968 · 207 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 45 recorded deaths. The most severe:
- 1930M6.5
Bismarck Sea
23 Dec 1930 · 266 km away
27 deathsModerate damage ($1–5M)tsunami
- 1970M7.3
Madang
31 Oct 1970 · 157 km away · intensity VIII
18 deaths$2 million damagetsunami
- 1857M8.0
Bismarck Sea
17 Apr 1857 · 299 km away
Moderate damage ($1–5M)tsunami
- 1873M8.0
Maclay Coast
1873 · 238 km away · intensity IX
Moderate damage ($1–5M)tsunami
- 1968M7.5
N Coast, Wewak, Dagua
23 Oct 1968 · 207 km away
Moderate damage ($1–5M)
- 1907M7.4
Bismarck Sea
15 Dec 1907 · 299 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.