Reviewed by USGSIndonesia21y ago
M3.9 earthquake 209 km WNW of Sabang, Indonesia
Sunday, February 20, 2005, 16:46:00 UTC · 6.409°N, 93.498°E
A magnitude 3.9 earthquake struck 209 km WNW of Sabang, Indonesia on Sunday, February 20, 2005, 16:46:00 UTC, at a depth of 30.0 km (shallow).
- Magnitude
- 3.9
- Minor · 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
11 tons of TNT
That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.
Tectonic setting
121 km
from the nearest mapped plate boundary, between the Sunda and Burma 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.2 on February 22, 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 524 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 · 82 km NW of this epicenter
- 7.0190 km WNW of Sabang, IndonesiaMay 17, 1955 · 62 km NE of this epicenter
- 6.975 km WSW of Banda Aceh, IndonesiaAugust 23, 1936 · 186 km SE of this epicenter
- 6.95 km W of Banda Aceh, IndonesiaApril 2, 1964 · 220 km SE of this epicenter
- 6.968 km WSW of Sabang, IndonesiaApril 4, 1983 · 155 km SE of this epicenter
- 6.8238 km WNW of Sabang, IndonesiaJanuary 20, 1917 · 68 km N of this epicenter
- 6.7171 km W of Meulaboh, IndonesiaDecember 9, 1929 · 280 km SE of this epicenter
- 6.7off the west coast of northern SumatraJanuary 1, 2005 · 197 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 9 recorded deaths. The most severe:
- 1936M7.3
Banda Aceh,Lhok Sukon,Lhoksemawe
23 Aug 1936 · 137 km away · intensity VIII
9 deathsModerate damage ($1–5M)tsunami
- 1881M7.9
Andaman I,Nicobar I
31 Dec 1881 · 263 km away
Severe damage ($5–24M)tsunami
- 1964M7.0
Banda Aceh
2 Apr 1964 · 250 km away · intensity VII
Severe damage ($5–24M)tsunami
- 1837M7.3
Banda Atjeh
29 Sep 1837 · 295 km away
Moderate damage ($1–5M)tsunami
- 1983M6.6
Sumatera: Banda Aceh
4 Apr 1983 · 155 km away · intensity VII
$1 million damage
- 1982M6.3
Little Nicobar Island
20 Jan 1982 · 82 km away · intensity VIII
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.