Reviewed by USGSIndonesia35y ago
M5.4 earthquake 87 km SE of Gorontalo, Indonesia
Wednesday, June 26, 1991, 23:07:06 UTC · 0.079°S, 123.558°E
A magnitude 5.4 earthquake struck 87 km SE of Gorontalo, Indonesia on Wednesday, June 26, 1991, 23:07:06 UTC, at a depth of 114.3 km (intermediate). It is the strongest earthquake within 300 km since an M5.4 on June 21, 1991.
- Magnitude
- 5.4
- Moderate · mw
- Depth
- 114 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
2 kilotons of TNT
That is about 1/8 of the Hiroshima bomb. It released about 4 times the energy of a magnitude 5.0.
Tectonic setting
76 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: intermediate
114 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 2 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.6 on July 18, 1991. 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 578 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11939 Sulawesi EarthquakeDecember 21, 1939 · 85 km W of this epicenter
- 7.8160 km W of Gorontalo, IndonesiaJanuary 22, 1905 · 228 km W of this epicenter
- 7.875 km NNW of Gorontalo, IndonesiaApril 18, 1990 · 161 km NW of this epicenter
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 264 km E of this epicenter
- 7.579 km NNW of Gorontalo, IndonesiaJune 20, 1991 · 166 km NW of this epicenter
- 7.433 km NW of Gorontalo, IndonesiaNovember 8, 1941 · 121 km NW of this epicenter
- 7.491 km SW of Gorontalo, IndonesiaAugust 6, 1984 · 116 km W of this epicenter
- 7.3108 km SE of Tondano, IndonesiaMay 5, 1908 · 224 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 128 recorded deaths. The most severe:
- 1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 225 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 264 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1990M7.6
Minahassa Peninsula: Bolaang-Gorontalo
18 Apr 1990 · 161 km away
3 deathsSevere damage ($5–24M)
- 1991M7.5
Minahassa: Gorontalo, Mamado
20 Jun 1991 · 166 km away · intensity VI
Severe damage ($5–24M)
- 1858M7.3
N. Moluccas Islands
13 Dec 1858 · 297 km away
Severe damage ($5–24M)tsunami
- 1939M8.0
Centrtal Sulawesi: Kalo,Luwuk,Sula I
21 Dec 1939 · 63 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.