Reviewed by USGSIndonesia100y ago
M5.5 earthquake 255 km N of Palu, Indonesia
Sunday, November 20, 1927, 17:14:48 UTC · 1.356°N, 120.307°E
A magnitude 5.5 earthquake struck 255 km N of Palu, Indonesia on Sunday, November 20, 1927, 17:14:48 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M5.7 on August 8, 1927.
- Magnitude
- 5.5
- Moderate · mw
- Depth
- 15 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
3 kilotons of TNT
That is about 1/6 of the Hiroshima bomb. It released about 5 times the energy of a magnitude 5.0.
Tectonic setting
93 km
from the nearest mapped plate boundary, between the Molucca Sea and Sunda plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
15 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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 10 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 · 168 km SE of this epicenter
- 7.1156 km NW of Gorontalo, IndonesiaJanuary 11, 1913 · 180 km E of this epicenter
- 6.5172 km ENE of Bontang, IndonesiaMay 14, 1921 · 170 km SW of this epicenter
- 6.435 km NNW of Palu, IndonesiaMay 25, 1907 · 224 km S of this epicenter
- 6.3Sulawesi, IndonesiaJuly 29, 1907 · 276 km S of this epicenter
- 6.3211 km SE of Tarakan, IndonesiaJune 24, 1907 · 168 km NW of this epicenter
- 6.3210 km ESE of Tarakan, IndonesiaMay 19, 1920 · 170 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 50 recorded deaths. The most severe:
- 1927M6.2
Sulawesi: Donggala
1 Dec 1927 · 254 km away · intensity VII
50 deathsSevere damage ($5–24M)tsunami
- 1921M6.2
Sangkulirang,Rending,Kariorang,Sekuran
14 May 1921 · 277 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1907M7.3
Talaud Islands: Karakelong Island
29 Mar 1907 · 262 km away
tsunami
- 1860
Sulawesi: Minahassa
Aug 1860 · 77 km away
tsunami
- 1920
N. Moluccas Islands
29 Jan 1920 · 295 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.