Reviewed by USGSIndonesia40y ago
M4.9 earthquake 143 km SE of Tondano, Indonesia
Saturday, September 13, 1986, 11:26:37 UTC · 0.473°N, 125.899°E
A magnitude 4.9 earthquake struck 143 km SE of Tondano, Indonesia on Saturday, September 13, 1986, 11:26:37 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.8 on September 11, 1986.
- Magnitude
- 4.9
- Light · mb
- Depth
- 33 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
338 tons of TNT
That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.
Tectonic setting
14 km
from the nearest mapped plate boundary, between the Molucca Sea and Birds Head plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 50 km
USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M5.1 on September 13, 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 736 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 10 km S of this epicenter
- 7.7121 km E of Bitung, IndonesiaAugust 10, 1968 · 117 km N of this epicenter
- 7.564 km NNW of Ternate, IndonesiaJune 25, 1907 · 172 km NE of this epicenter
- 7.5146 km NW of Ternate, IndonesiaAugust 14, 1986 · 162 km NE of this epicenter
- 7.3108 km SE of Tondano, IndonesiaMay 5, 1908 · 46 km W of this epicenter
- 7.2182 km WNW of Tobelo, IndonesiaOctober 10, 1938 · 225 km N of this epicenter
- 7.1129 km WNW of Ternate, IndonesiaMay 3, 1925 · 95 km NE of this epicenter
- 7.1197 km SSE of Sofifi, IndonesiaApril 16, 1963 · 290 km SE 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 · 162 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1855
Maluku: Ternate Island
14 Jul 1855 · 160 km away · intensity IX
34 deathsModerate damage ($1–5M)
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 10 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1858M7.3
N. Moluccas Islands
13 Dec 1858 · 60 km away
Severe damage ($5–24M)tsunami
- 1889M8.0
N. Moluccas Islands
6 Sep 1889 · 70 km away
Moderate damage ($1–5M)tsunami
- 1859M7.3
Sulawesi
29 Jul 1859 · 68 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.