Reviewed by USGSIndonesia28y ago
M4.6 earthquake 228 km ESE of Luwuk, Indonesia
Friday, January 8, 1999, 21:02:02 UTC · 1.880°S, 124.626°E
A magnitude 4.6 earthquake struck 228 km ESE of Luwuk, Indonesia on Friday, January 8, 1999, 21:02:02 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on December 29, 1998.
- Magnitude
- 4.6
- 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
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
170 km
from the nearest mapped plate boundary, between the Molucca Sea and Banda Sea plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
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 M4.4 on February 7, 1999. 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 458 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.21965 Ceram Sea EarthquakeJanuary 24, 1965 · 170 km SE of this epicenter
- 8.11939 Sulawesi EarthquakeDecember 21, 1939 · 291 km NW of this epicenter
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 288 km NE of this epicenter
- 7.7264 km ESE of Luwuk, IndonesiaNovember 29, 1998 · 36 km SE of this epicenter
- 7.3108 km SE of Tondano, IndonesiaMay 5, 1908 · 283 km N of this epicenter
- 7.1170 km WNW of Ambon, IndonesiaJune 9, 1938 · 275 km SE of this epicenter
- 6.8Molucca SeaDecember 9, 1993 · 292 km NE of this epicenter
- 6.8161 km S of Luwuk, IndonesiaNovember 19, 1913 · 242 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 119 recorded deaths. The most severe:
- 1965M7.6
Sanana Island
24 Jan 1965 · 174 km away
71 deathsModerate damage ($1–5M)tsunami
- 1998M7.7
Mangole, Manado, Taliabu
29 Nov 1998 · 36 km away · intensity VII
41 deaths$200 million damagetsunami
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 288 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1939M8.0
Centrtal Sulawesi: Kalo,Luwuk,Sula I
21 Dec 1939 · 276 km away
Moderate damage ($1–5M)tsunami
- 1859M7.3
Sulawesi
29 Jul 1859 · 231 km away
Moderate damage ($1–5M)tsunami
- 1975M6.6
Sanana Island
5 Mar 1975 · 180 km away · intensity VI
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.