Reviewed by USGSIndonesia42y ago
M4.8 earthquake 73 km S of Gorontalo, Indonesia
Saturday, August 11, 1984, 00:17:16 UTC · 0.124°S, 122.985°E
A magnitude 4.8 earthquake struck 73 km S of Gorontalo, Indonesia on Saturday, August 11, 1984, 00:17:16 UTC, at a depth of 142.2 km (intermediate). It is the strongest earthquake within 300 km since an M7.4 on August 6, 1984.
- Magnitude
- 4.8
- Light · mb
- Depth
- 142 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 earthquake
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
130 km
from the nearest mapped plate boundary, between the Molucca Sea and Sunda plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
142 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 345 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 · 24 km NW of this epicenter
- 7.8160 km W of Gorontalo, IndonesiaJanuary 22, 1905 · 172 km NW of this epicenter
- 7.7120 km NE of Palu, IndonesiaMay 19, 1938 · 272 km W of this epicenter
- 7.433 km NW of Gorontalo, IndonesiaNovember 8, 1941 · 97 km N of this epicenter
- 7.491 km SW of Gorontalo, IndonesiaAugust 6, 1984 · 52 km W of this epicenter
- 7.3108 km SE of Tondano, IndonesiaMay 5, 1908 · 287 km E of this epicenter
- 7.1156 km NW of Gorontalo, IndonesiaJanuary 11, 1913 · 204 km NW of this epicenter
- 6.8161 km S of Luwuk, IndonesiaNovember 19, 1913 · 257 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 17 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 187 recorded deaths. The most severe:
- 1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 274 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1927M6.2
Sulawesi: Donggala
1 Dec 1927 · 262 km away · intensity VII
50 deathsSevere damage ($5–24M)tsunami
- 1938M7.7
Sulawesi Island
19 May 1938 · 272 km away · intensity IX
17 deathsSevere damage ($5–24M)tsunami
- 1983M6.1
Central Sulawesi
25 Oct 1983 · 275 km away · intensity VII
2 deathsModerate damage ($1–5M)
- 1939M8.0
Centrtal Sulawesi: Kalo,Luwuk,Sula I
21 Dec 1939 · 14 km away
Moderate damage ($1–5M)tsunami
- 1859M7.3
Sulawesi
29 Jul 1859 · 280 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.