Reviewed by USGSIndonesia17y ago
M7.6 earthquake 30 km WSW of Pariaman, Indonesia
Wednesday, September 30, 2009, 10:16:09 UTC · 0.720°S, 99.867°E
A magnitude 7.6 earthquake struck 30 km WSW of Pariaman, Indonesia on Wednesday, September 30, 2009, 10:16:09 UTC, at a depth of 81.0 km (intermediate). USGS received 1,027 “Did You Feel It?” reports, with a maximum reported intensity of VIII (severe). It is the strongest earthquake within 300 km since an M7.9 on September 12, 2007.
- Magnitude
- 7.6
- Major · mwc
- Depth
- 81 km
- Intermediate
- Felt reports
- 1,027
- Max intensity VIII
- Est. shaking
- VIII
- Severe (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
3.8 megatons of TNT
That is about 252 times the Hiroshima bomb. It released about 7,943 times the energy of a magnitude 5.0.
Tectonic setting
225 km
from the nearest mapped plate boundary, between the Sunda and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
81 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
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| Singapore, _no region, Singapore | III · Weak | 487 | 503 km |
| Kuala Lumpur, Kuala Lumpur, Malaysia | III · Weak | 218 | 482 km |
| Petaling Jaya, Selangor, Malaysia | III · Weak | 70 | 472 km |
| Shah Alam, Selangor, Malaysia | III · Weak | 26 | 466 km |
| Subang Jaya, Selangor, Malaysia | III · Weak | 21 | 473 km |
| Kajang-Sungai Chua, Selangor, Malaysia | IV · Light | 14 | 467 km |
| Pekan Baru, Riau, Indonesia | III · Weak | 13 | 238 km |
| Padang, Sumatera Barat, Indonesia | VIII · Severe | 11 | 100 km |
| Klang, Selangor, Malaysia | III · Weak | 11 | 458 km |
| Johor Bahru, Johor, Malaysia | IV · Light | 10 | 502 km |
| Georgetown, Pulau Pinang, Malaysia | III · Weak | 10 | 680 km |
| Balakong, Selangor, Malaysia | IV · Light | 9 | 471 km |
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 200 km
USGS lists 16 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.4 on September 30, 2009. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.5121 km WSW of Padang, Indonesia17y ago · 100 km SW of this epicenter
- 4.0153 km WSW of Padang, Indonesia17y ago · 133 km SW of this epicenter
- 4.441 km SW of Pariaman, Indonesia17y ago · 14 km SW of this epicenter
- 4.463 km S of Padang, Indonesia17y ago · 108 km SE of this epicenter
- 4.7Kepulauan Mentawai region, Indonesia17y ago · 111 km SW of this epicenter
- 4.4127 km WSW of Padang, Indonesia17y ago · 108 km SW of this epicenter
- 5.089 km SSE of Padang, Indonesia17y ago · 136 km SE of this epicenter
- 4.614 km S of Pariaman, Indonesia17y ago · 29 km E of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 441 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 · 238 km SE of this epicenter
- 7.726 km S of Sijunjung, IndonesiaJune 9, 1943 · 121 km E of this epicenter
- 7.6212 km W of Pariaman, IndonesiaDecember 28, 1935 · 187 km W of this epicenter
- 7.676 km SSW of Sungai Penuh, IndonesiaJune 3, 1909 · 266 km SE of this epicenter
- 7.2164 km WSW of Sungai Penuh, IndonesiaFebruary 25, 2008 · 197 km S of this epicenter
- 7.1190 km SSW of Sibolga, IndonesiaNovember 17, 1984 · 229 km NW of this epicenter
- 7.095 km W of Pariaman, IndonesiaApril 1, 1998 · 70 km W of this epicenter
- 7.0153 km SSW of Padang, IndonesiaSeptember 13, 2007 · 159 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 28 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 · 0 km away
1,117 deaths$2.2 billion damagetsunami
- 1861M8.5
Lagundi, Simuk, Tello I
16 Feb 1861 · 265 km away · intensity IX
1,105 deathsModerate damage ($1–5M)tsunami
- 1861M7.0
Sw. Sumatra
9 Mar 1861 · 223 km away
950 deathsSevere damage ($5–24M)tsunami
- 1797M8.0
Sw. Sumatra
10 Feb 1797 · 125 km away · intensity IX
300 deathsModerate damage ($1–5M)tsunami
- 1995M6.8
Sumatera, Jambi Province
6 Oct 1995 · 228 km away
84 deathsExtreme damage ($25M+)
- 2007M6.4
Sumatra: Southern
6 Mar 2007 · 75 km away · intensity VIII
67 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.