Reviewed by USGSIndonesia21y ago
M4.7 earthquake 245 km SW of Sibolga, Indonesia
Monday, September 19, 2005, 11:09:18 UTC · 0.095°S, 97.545°E
A magnitude 4.7 earthquake struck 245 km SW of Sibolga, Indonesia on Monday, September 19, 2005, 11:09:18 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on September 15, 2005.
- Magnitude
- 4.7
- 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
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
41 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.0 on September 25, 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 339 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 · 247 km N of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 80 km E of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 63 km NE of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 197 km E of this epicenter
- 7.0122 km W of Pariaman, IndonesiaMay 8, 1946 · 179 km SE of this epicenter
- 7.0102 km SW of Padangsidempuan, IndonesiaFebruary 4, 1971 · 155 km NE of this epicenter
- 6.9181 km SW of Sibolga, IndonesiaDecember 4, 1974 · 64 km NE of this epicenter
- 6.989 km WSW of Singkil, IndonesiaMay 19, 2005 · 238 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 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 · 247 km away
1,319 deaths$37 million damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 101 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 52 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 162 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1987M6.6
Sumatera: N, Tarutung-Lake Toba,
25 Apr 1987 · 299 km away
2 deaths$1 million damage
- 1843M7.3
Sw. Sumatra
5 Jan 1843 · 184 km away · intensity XI
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.