Reviewed by USGSIndonesia21y ago
M4.6 earthquake 268 km SW of Sibolga, Indonesia
Wednesday, July 13, 2005, 00:48:30 UTC · 0.175°S, 97.302°E
A magnitude 4.6 earthquake struck 268 km SW of Sibolga, Indonesia on Wednesday, July 13, 2005, 00:48:30 UTC, at a depth of 23.9 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on July 12, 2005.
- Magnitude
- 4.6
- Light · mb
- Depth
- 24 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
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
13 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
24 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on July 31, 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 284 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 · 252 km N of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 105 km E of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 91 km NE of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 222 km E of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 201 km E of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 183 km NE of this epicenter
- 6.9181 km SW of Sibolga, IndonesiaDecember 4, 1974 · 87 km NE of this epicenter
- 6.989 km WSW of Singkil, IndonesiaMay 19, 2005 · 242 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,674 recorded deaths. The most severe:
- 2005M8.6
Sumatera: Sw
28 Mar 2005 · 252 km away
1,319 deaths$37 million damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 94 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 80 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 190 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 202 km away · intensity XI
Severe damage ($5–24M)tsunami
- 1935M7.9
N Sumatera: Batu I,Padang,Sibolga
28 Dec 1935 · 107 km away · intensity VIII
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.