Reviewed by USGSPapua New Guinea41y ago
M4.3 earthquake 155 km E of Kokopo, Papua New Guinea
Monday, October 28, 1985, 01:14:24 UTC · 4.613°S, 153.642°E
A magnitude 4.3 earthquake struck 155 km E of Kokopo, Papua New Guinea on Monday, October 28, 1985, 01:14:24 UTC, at a depth of 94.0 km (intermediate).
- Magnitude
- 4.3
- Light · mb
- Depth
- 94 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 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
66 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: intermediate
94 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 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 936 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 · 32 km SE of this epicenter
- 8.11971 Bougainville EarthquakeJuly 26, 1971 · 58 km SW of this epicenter
- 8.01971 New Britain EarthquakeJuly 14, 1971 · 98 km S of this epicenter
- 8.060 km SE of Kokopo, Papua New GuineaJanuary 1, 1916 · 114 km W of this epicenter
- 7.956 km WSW of Panguna, Papua New GuineaJuly 20, 1975 · 270 km SE of this epicenter
- 7.874 km SSW of Kokopo, Papua New GuineaFebruary 2, 1920 · 184 km W of this epicenter
- 7.7152 km SE of Kokopo, Papua New GuineaSeptember 29, 1946 · 74 km SW of this epicenter
- 7.6157 km ESE of Kokopo, Papua New GuineaMarch 18, 1983 · 31 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 30 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 525 recorded deaths. The most severe:
- 1937
Keravia, Rabaul, Kokopo
28 May 1937 · 164 km away · intensity VIII
507 deathsLimited damage (under $1M)tsunami
- 1983M6.4
Ulawun, Rabaul
22 Dec 1983 · 215 km away · intensity V
10 deaths$25 million damage
- 1941M7.4
Bismarck Sea
13 Jan 1941 · 181 km away
4 deathsModerate damage ($1–5M)tsunami
- 1971M7.9
New Ireland: Bougainville
14 Jul 1971 · 103 km away · intensity IX
3 deathsUnder $1 million damagetsunami
- 1878
Bismarck Sea
4 Feb 1878 · 160 km away
1 deathtsunami
- 1975M7.9
Bismarck Sea: Bougainville
20 Jul 1975 · 270 km away · intensity VIII
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.