Reviewed by USGSIndonesia17y ago
M4.6 earthquake 14 km S of Pariaman, Indonesia
Wednesday, October 7, 2009, 03:19:01 UTC · 0.750°S, 100.124°E
A magnitude 4.6 earthquake struck 14 km S of Pariaman, Indonesia on Wednesday, October 7, 2009, 03:19:01 UTC, at a depth of 90.2 km (intermediate). It is the strongest earthquake within 300 km since an M4.8 on October 5, 2009.
- Magnitude
- 4.6
- Light · mb
- Depth
- 90 km
- Intermediate
- 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
222 km
from the nearest mapped plate boundary, between the North Andes and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
90 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 M4.4 on October 26, 2009. 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 440 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.987 km SW of Sungai Penuh, IndonesiaSeptember 12, 2007 · 223 km S of this epicenter
- 7.726 km S of Sijunjung, IndonesiaJune 9, 1943 · 93 km E of this epicenter
- 7.630 km WSW of Pariaman, IndonesiaSeptember 30, 2009 · 29 km W of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 216 km W of this epicenter
- 7.676 km SSW of Sungai Penuh, IndonesiaJune 3, 1909 · 248 km SE of this epicenter
- 7.2164 km WSW of Sungai Penuh, IndonesiaFebruary 25, 2008 · 194 km S of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 256 km NW of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 99 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 27 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,638 recorded deaths. The most severe:
- 2009M7.5
Sumatra: Padang
30 Sep 2009 · 29 km away
1,117 deaths$2.2 billion damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 293 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 251 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 150 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1995M6.8
Sumatera, Jambi Province
6 Oct 1995 · 205 km away
84 deathsExtreme damage ($25M+)
- 2007M6.4
Sumatra: Southern
6 Mar 2007 · 50 km away · intensity VIII
67 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.