Reviewed by USGS88y ago
M8.1 earthquake 1939 Sulawesi Earthquake
Thursday, December 21, 1939, 21:00:45 UTC · 0.018°S, 122.793°E
A magnitude 8.1 earthquake struck 1939 Sulawesi Earthquake on Thursday, December 21, 1939, 21:00:45 UTC, at a depth of 150.0 km (intermediate). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 8.1
- Great · mw
- Depth
- 150 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
21 megatons of TNT
That is about 1,415 times the Hiroshima bomb. It released about 44,668 times the energy of a magnitude 5.0.
Tectonic setting
141 km
from the nearest mapped plate boundary, between the Molucca Sea and Sunda plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
150 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 400 km
USGS has not published any M2.5+ earthquake within 400 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 28 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 · 148 km NW of this epicenter
- 7.7120 km NE of Palu, IndonesiaMay 19, 1938 · 251 km W of this epicenter
- 7.1156 km NW of Gorontalo, IndonesiaJanuary 11, 1913 · 182 km NW of this epicenter
- 6.8161 km S of Luwuk, IndonesiaNovember 19, 1913 · 266 km S of this epicenter
- 6.8109 km WSW of Luwuk, IndonesiaMarch 17, 1909 · 170 km SW of this epicenter
- 6.730 km N of Luwuk, IndonesiaDecember 23, 1912 · 73 km S of this epicenter
- 6.628 km E of Poso, IndonesiaDecember 5, 1923 · 251 km SW of this epicenter
- 6.469 km NNE of Luwuk, IndonesiaSeptember 11, 1922 · 38 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 185 recorded deaths. The most severe:
- 1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 283 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1927M6.2
Sulawesi: Donggala
1 Dec 1927 · 246 km away · intensity VII
50 deathsSevere damage ($5–24M)tsunami
- 1938M7.7
Sulawesi Island
19 May 1938 · 251 km away · intensity IX
17 deathsSevere damage ($5–24M)tsunami
- 1939M8.0
Centrtal Sulawesi: Kalo,Luwuk,Sula I
21 Dec 1939 · 23 km away
Moderate damage ($1–5M)tsunami
- 1907
Sulawesi: Lemo, Colo, Anja, Olu Congko
30 Jul 1907 · 297 km away · intensity VIII
Moderate damage ($1–5M)
- 1905M8.4
Minahassa Peninsula
22 Jan 1905 · 116 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.