Reviewed by USGSIndonesia40y ago
M5.6 earthquake 47 km ENE of Sofifi, Indonesia
Tuesday, September 9, 1986, 15:58:22 UTC · 0.927°N, 127.944°E
A magnitude 5.6 earthquake struck 47 km ENE of Sofifi, Indonesia on Tuesday, September 9, 1986, 15:58:22 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.6 on August 24, 1986.
- Magnitude
- 5.6
- Moderate · mw
- Depth
- 33 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- 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
4 kilotons of TNT
That is about 1/4 of the Hiroshima bomb. It released about 8 times the energy of a magnitude 5.0.
Tectonic setting
112 km
from the nearest mapped plate boundary, between the Sunda and Birds Head plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
33 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 687 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.790 km NE of Tobelo, IndonesiaSeptember 8, 1966 · 173 km N of this epicenter
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 237 km W of this epicenter
- 7.7121 km E of Bitung, IndonesiaAugust 10, 1968 · 201 km W of this epicenter
- 7.564 km NNW of Ternate, IndonesiaJune 25, 1907 · 97 km NW of this epicenter
- 7.5146 km NW of Ternate, IndonesiaAugust 14, 1986 · 185 km NW of this epicenter
- 7.4193 km W of Sorong, IndonesiaOctober 7, 1923 · 298 km SE of this epicenter
- 7.3108 km SE of Tondano, IndonesiaMay 5, 1908 · 277 km W of this epicenter
- 7.2182 km WNW of Tobelo, IndonesiaOctober 10, 1938 · 228 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 41 recorded deaths. The most severe:
- 1855
Maluku: Ternate Island
14 Jul 1855 · 73 km away · intensity IX
34 deathsModerate damage ($1–5M)
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 237 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1858M7.3
N. Moluccas Islands
13 Dec 1858 · 216 km away
Severe damage ($5–24M)tsunami
- 1889M8.0
N. Moluccas Islands
6 Sep 1889 · 189 km away
Moderate damage ($1–5M)tsunami
- 1859M7.3
Sulawesi
29 Jul 1859 · 290 km away
Moderate damage ($1–5M)tsunami
- 1840
Maluku: Ternate Island
14 Feb 1840 · 70 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.