Reviewed by USGSIndonesia21y ago
M4.2 earthquake 236 km SSW of Singkil, Indonesia
Monday, July 11, 2005, 19:12:03 UTC · 0.257°N, 97.129°E
A magnitude 4.2 earthquake struck 236 km SSW of Singkil, Indonesia on Monday, July 11, 2005, 19:12:03 UTC, at a depth of 33.3 km (shallow).
- Magnitude
- 4.2
- 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
19 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
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 5 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on July 29, 2005. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.5218 km SW of Sibolga, Indonesia21y ago · 46 km E of this epicenter
- 4.7224 km SSW of Singkil, Indonesia21y ago · 20 km E of this epicenter
- 4.4225 km SSW of Singkil, Indonesia21y ago · 20 km E of this epicenter
- 4.8229 km SSW of Singkil, Indonesia21y ago · 16 km E of this epicenter
- 4.0256 km SW of Sibolga, Indonesia21y ago · 29 km SE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 301 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 · 203 km N of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 137 km SE of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 100 km E of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 253 km E of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 238 km SE of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 184 km E of this epicenter
- 6.928 km NNE of Sinabang, IndonesiaNovember 4, 1917 · 281 km N of this epicenter
- 6.9181 km SW of Sibolga, IndonesiaDecember 4, 1974 · 81 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,676 recorded deaths. The most severe:
- 2005M8.6
Sumatera: Sw
28 Mar 2005 · 203 km away
1,319 deaths$37 million damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 146 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 101 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 210 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1987M6.6
Sumatera: N, Tarutung-Lake Toba,
25 Apr 1987 · 293 km away
2 deaths$1 million damage
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 169 km away · intensity XI
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.