Reviewed by USGSIndonesia21y ago
M3.8 earthquake 216 km SSW of Singkil, Indonesia
Friday, September 23, 2005, 20:28:25 UTC · 0.411°N, 97.236°E
A magnitude 3.8 earthquake struck 216 km SSW of Singkil, Indonesia on Friday, September 23, 2005, 20:28:25 UTC, at a depth of 30.0 km (shallow).
- Magnitude
- 3.8
- 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
8 tons of TNT
That is about 1/1,992 of the Hiroshima bomb. A magnitude 5.0 releases about 63 times more energy.
Tectonic setting
37 km
from the nearest mapped plate boundary, between the Sunda and Australian 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.6 on October 15, 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 338 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 · 187 km N of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 136 km SE of this epicenter
- 7.450 km NW of Sinabang, IndonesiaNovember 2, 2002 · 297 km NW of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 91 km E of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 249 km SE of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 236 km SE of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 169 km E of this epicenter
- 6.928 km NNE of Sinabang, IndonesiaNovember 4, 1917 · 267 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,679 recorded deaths. The most severe:
- 2005M8.6
Sumatera: Sw
28 Mar 2005 · 187 km away
1,319 deaths$37 million damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 160 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 96 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 201 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 2002M7.3
Sumatera: Simeulue
2 Nov 2002 · 297 km away
3 deathsSevere damage ($5–24M)
- 1987M6.6
Sumatera: N, Tarutung-Lake Toba,
25 Apr 1987 · 273 km away
2 deaths$1 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.