Reviewed by USGSIndonesia40y ago
M4.7 earthquake 78 km NNW of Ternate, Indonesia
Friday, September 26, 1986, 01:49:45 UTC · 1.447°N, 127.109°E
A magnitude 4.7 earthquake struck 78 km NNW of Ternate, Indonesia on Friday, September 26, 1986, 01:49:45 UTC, at a depth of 144.4 km (intermediate). It is the strongest earthquake within 300 km since an M5.0 on September 26, 1986.
- Magnitude
- 4.7
- Light · mb
- Depth
- 144 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
79 km
from the nearest mapped plate boundary, between the Birds Head and Sunda plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
144 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 lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.0 on October 21, 1986. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 819 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 · 186 km NE of this epicenter
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 180 km SW of this epicenter
- 7.7121 km E of Bitung, IndonesiaAugust 10, 1968 · 99 km W of this epicenter
- 7.564 km NNW of Ternate, IndonesiaJune 25, 1907 · 14 km SE of this epicenter
- 7.5146 km NW of Ternate, IndonesiaAugust 14, 1986 · 76 km NW of this epicenter
- 7.5210 km SSE of Sarangani, PhilippinesAugust 17, 1912 · 267 km NW of this epicenter
- 7.3108 km SE of Tondano, IndonesiaMay 5, 1908 · 208 km SW of this epicenter
- 7.2182 km WNW of Tobelo, IndonesiaOctober 10, 1938 · 125 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 159 recorded deaths. The most severe:
- 1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 251 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1855
Maluku: Ternate Island
14 Jul 1855 · 75 km away · intensity IX
34 deathsModerate damage ($1–5M)
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 180 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1858M7.3
N. Moluccas Islands
13 Dec 1858 · 133 km away
Severe damage ($5–24M)tsunami
- 1889M8.0
N. Moluccas Islands
6 Sep 1889 · 108 km away
Moderate damage ($1–5M)tsunami
- 1859M7.3
Sulawesi
29 Jul 1859 · 240 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.