Reviewed by USGS52y ago
M4.8 earthquake in D'Entrecasteaux Islands region
Wednesday, October 23, 1974, 08:52:09 UTC · 8.405°S, 153.022°E
A magnitude 4.8 earthquake struck in D'Entrecasteaux Islands region on Wednesday, October 23, 1974, 08:52:09 UTC, at a depth of 88.0 km (intermediate). It is the strongest earthquake within 300 km since an M7.2 on October 23, 1974.
- Magnitude
- 4.8
- Light · mb
- Depth
- 88 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
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
16 km
from the nearest mapped plate boundary, between the Solomon Sea and Woodlark plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
88 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 145 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.885 km S of Panguna, Papua New GuineaJanuary 30, 1939 · 299 km NE of this epicenter
- 7.5199 km SSE of Kokopo, Papua New GuineaAugust 17, 1972 · 264 km N of this epicenter
- 7.2282 km SW of Panguna, Papua New GuineaOctober 23, 1974 · 111 km E of this epicenter
- 7.0133 km WSW of Panguna, Papua New GuineaJanuary 29, 1932 · 244 km NE of this epicenter
- 7.0170 km SE of Kimbe, Papua New GuineaMarch 4, 1905 · 279 km NW of this epicenter
- 6.973 km WSW of Panguna, Papua New GuineaSeptember 9, 1941 · 290 km NE of this epicenter
- 6.9160 km WSW of Panguna, Papua New GuineaSeptember 23, 1937 · 225 km NE of this epicenter
- 6.869 km WSW of Panguna, Papua New GuineaApril 24, 1931 · 293 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5 recorded deaths. The most severe:
- 1939M7.7
Bougainville Island
30 Jan 1939 · 299 km away
5 deathsModerate damage ($1–5M)tsunami
- 1907M7.7
New Britain
4 May 1907 · 125 km away
- 1972M7.1
W. Solomon Sea
17 Aug 1972 · 268 km away · intensity V
tsunami
- 1960M6.6
W. Solomon Sea
11 Jun 1960 · 136 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.