Reviewed by USGS21y ago
M4.1 earthquake off the west coast of northern Sumatra
Wednesday, January 26, 2005, 14:41:57 UTC · 4.935°N, 92.497°E
A magnitude 4.1 earthquake struck off the west coast of northern Sumatra on Wednesday, January 26, 2005, 14:41:57 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
21 km
from the nearest mapped plate boundary, between the Burma and Indian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 M4.8 on February 17, 2005. 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 225 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2284 km WNW of Sabang, IndonesiaDecember 26, 2004 · 225 km N of this epicenter
- 7.0190 km WNW of Sabang, IndonesiaMay 17, 1955 · 259 km NE of this epicenter
- 6.975 km WSW of Banda Aceh, IndonesiaAugust 23, 1936 · 248 km E of this epicenter
- 6.968 km WSW of Sabang, IndonesiaApril 4, 1983 · 261 km E of this epicenter
- 6.8238 km WNW of Sabang, IndonesiaJanuary 20, 1917 · 257 km NE of this epicenter
- 6.7171 km W of Meulaboh, IndonesiaDecember 9, 1929 · 248 km E of this epicenter
- 6.7off the west coast of northern SumatraJanuary 1, 2005 · 28 km NW of this epicenter
- 6.6Nicobar Islands, India regionApril 7, 1973 · 257 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 9 recorded deaths. The most severe:
- 1936M7.3
Banda Aceh,Lhok Sukon,Lhoksemawe
23 Aug 1936 · 276 km away · intensity VIII
9 deathsModerate damage ($1–5M)tsunami
- 1983M6.6
Sumatera: Banda Aceh
4 Apr 1983 · 261 km away · intensity VII
$1 million damage
- 1982M6.3
Little Nicobar Island
20 Jan 1982 · 279 km away · intensity VIII
Moderate damage ($1–5M)
- 1847
Little Nicobar Island
31 Oct 1847 · 296 km away · intensity X
Limited damage (under $1M)tsunami
- 1955M7.3
Little Nicobar Island
17 May 1955 · 241 km away
tsunami
- 1949M6.7
Banda Aceh
9 May 1949 · 277 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.