Reviewed by USGSIndonesia20y ago
M4.1 earthquake 136 km SSW of Sibolga, Indonesia
Sunday, February 26, 2006, 06:18:40 UTC · 0.707°N, 98.105°E
A magnitude 4.1 earthquake struck 136 km SSW of Sibolga, Indonesia on Sunday, February 26, 2006, 06:18:40 UTC, at a depth of 30.0 km (shallow).
- Magnitude
- 4.1
- Light · mb
- Depth
- 30 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
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
138 km
from the nearest mapped plate boundary, between the Sunda and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
30 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.3 on March 27, 2006. 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 361 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.678 km WSW of Singkil, IndonesiaMarch 28, 2005 · 189 km NW of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 111 km S of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 57 km S of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 189 km SE of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 190 km SE of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 71 km E of this epicenter
- 6.928 km NNE of Sinabang, IndonesiaNovember 4, 1917 · 284 km NW of this epicenter
- 6.9181 km SW of Sibolga, IndonesiaDecember 4, 1974 · 45 km SW 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 3,683 recorded deaths. The most severe:
- 2005M8.6
Sumatera: Sw
28 Mar 2005 · 189 km away
1,319 deaths$37 million damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 201 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 78 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 127 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 2006M5.8
Sumatera: Northern, Muarasipongi
17 Dec 2006 · 195 km away
7 deathsSevere damage ($5–24M)
- 1987M6.6
Sumatera: N, Tarutung-Lake Toba,
25 Apr 1987 · 191 km away
2 deaths$1 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.