Reviewed by USGSIndonesia40y ago
M5.1 earthquake 102 km WNW of Tobelo, Indonesia
Thursday, April 16, 1987, 07:01:51 UTC · 1.937°N, 127.116°E
A magnitude 5.1 earthquake struck 102 km WNW of Tobelo, Indonesia on Thursday, April 16, 1987, 07:01:51 UTC, at a depth of 125.5 km (intermediate). It is the strongest earthquake within 300 km since an M5.1 on April 14, 1987.
- Magnitude
- 5.1
- Moderate · mb
- Depth
- 126 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
674 tons of TNT
That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.
Tectonic setting
44 km
from the nearest mapped plate boundary, between the Sunda and Birds Head plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
126 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 75 km
USGS lists 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.2 on May 4, 1987. 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 853 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8161 km SE of Sarangani, PhilippinesApril 1, 1936 · 271 km N of this epicenter
- 7.790 km NE of Tobelo, IndonesiaSeptember 8, 1966 · 161 km E of this epicenter
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 220 km SW of this epicenter
- 7.7121 km E of Bitung, IndonesiaAugust 10, 1968 · 112 km SW of this epicenter
- 7.564 km NNW of Ternate, IndonesiaJune 25, 1907 · 67 km S of this epicenter
- 7.5146 km NW of Ternate, IndonesiaAugust 14, 1986 · 68 km W of this epicenter
- 7.5210 km SSE of Sarangani, PhilippinesAugust 17, 1912 · 221 km NW of this epicenter
- 7.5273 km N of Tobelo, IndonesiaOctober 23, 1914 · 272 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 20 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,965 recorded deaths. The most severe:
- 1856
Sangihe Pulau (Volcanic)
2 Mar 1856 · 263 km away
2,806 deathsSevere damage ($5–24M)tsunami
- 1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 257 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1855
Maluku: Ternate Island
14 Jul 1855 · 128 km away · intensity IX
34 deathsModerate damage ($1–5M)
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 220 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1858M7.3
N. Moluccas Islands
13 Dec 1858 · 162 km away
Severe damage ($5–24M)tsunami
- 1889M8.0
N. Moluccas Islands
6 Sep 1889 · 142 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.