Reviewed by USGSPapua New Guinea40y ago
M5.3 earthquake 33 km SSW of Angoram, Papua New Guinea
Sunday, July 6, 1986, 21:40:12 UTC · 4.341°S, 143.957°E
A magnitude 5.3 earthquake struck 33 km SSW of Angoram, Papua New Guinea on Sunday, July 6, 1986, 21:40:12 UTC, at a depth of 122.2 km (intermediate). It is the strongest earthquake within 300 km since an M7.2 on June 24, 1986.
- Magnitude
- 5.3
- Moderate · mb
- Depth
- 122 km
- Intermediate
- 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
1 kilotons of TNT
That is about 1/11 of the Hiroshima bomb. It released about 3 times the energy of a magnitude 5.0.
Tectonic setting
60 km
from the nearest mapped plate boundary, between the South Bismarck and Woodlark plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
122 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 M4.7 on August 2, 1986. 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 288 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8New Guinea, Papua New GuineaSeptember 20, 1935 · 291 km W of this epicenter
- 7.650 km N of Wewak, Papua New GuineaJuly 3, 1918 · 145 km N of this epicenter
- 7.593 km SW of Aitape, Papua New GuineaJuly 29, 1917 · 257 km W of this epicenter
- 7.349 km NNE of Angoram, Papua New GuineaMay 7, 1907 · 83 km N of this epicenter
- 7.244 km SSW of Angoram, Papua New GuineaJune 24, 1986 · 12 km S of this epicenter
- 7.1132 km NNE of Wewak, Papua New GuineaAugust 26, 1906 · 208 km N of this epicenter
- 7.143 km SW of Aitape, Papua New GuineaAugust 7, 1931 · 240 km NW of this epicenter
- 7.165 km ENE of Wewak, Papua New GuineaApril 27, 1909 · 117 km N 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 18 recorded deaths. The most severe:
- 1970M7.3
Madang
31 Oct 1970 · 179 km away · intensity VIII
18 deaths$2 million damagetsunami
- 1873M8.0
Maclay Coast
1873 · 260 km away · intensity IX
Moderate damage ($1–5M)tsunami
- 1968M7.5
N Coast, Wewak, Dagua
23 Oct 1968 · 128 km away
Moderate damage ($1–5M)
- 1907M7.4
Bismarck Sea
15 Dec 1907 · 213 km away
Moderate damage ($1–5M)tsunami
- 1984M6.6
Karkar
27 Mar 1984 · 208 km away · intensity VIII
Moderate damage ($1–5M)
- 1979M6.2
E, Mt Hagen
25 Jun 1979 · 193 km away
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.