Reviewed by USGSIndonesia104y ago
M6.6 earthquake 28 km E of Poso, Indonesia
Wednesday, December 5, 1923, 22:35:10 UTC · 1.401°S, 121.004°E
A magnitude 6.6 earthquake struck 28 km E of Poso, Indonesia on Wednesday, December 5, 1923, 22:35:10 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on November 19, 1913.
- Magnitude
- 6.6
- Strong · mw
- Depth
- 35 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
104 kilotons of TNT
That is about 7 times the Hiroshima bomb. It released about 219 times the energy of a magnitude 5.0.
Tectonic setting
40 km
from the nearest mapped plate boundary, between the Molucca Sea and Banda Sea plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
35 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 9 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8160 km W of Gorontalo, IndonesiaJanuary 22, 1905 · 234 km N of this epicenter
- 6.8161 km S of Luwuk, IndonesiaNovember 19, 1913 · 200 km SE of this epicenter
- 6.8109 km WSW of Luwuk, IndonesiaMarch 17, 1909 · 95 km E of this epicenter
- 6.730 km N of Luwuk, IndonesiaDecember 23, 1912 · 210 km NE of this epicenter
- 6.469 km NNE of Luwuk, IndonesiaSeptember 11, 1922 · 244 km NE of this epicenter
- 6.454 km NE of Luwuk, IndonesiaFebruary 23, 1923 · 255 km E of this epicenter
- 6.435 km NNW of Palu, IndonesiaMay 25, 1907 · 162 km NW of this epicenter
- 6.3Sulawesi, IndonesiaJuly 29, 1907 · 114 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 2 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1907
Sulawesi: Lemo, Colo, Anja, Olu Congko
30 Jul 1907 · 67 km away · intensity VIII
Moderate damage ($1–5M)
- 1860
Sulawesi: Minahassa
Aug 1860 · 300 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.