M3.9 earthquake 179 km SW of Sungai Penuh, Indonesia

Sunday, October 21, 2007, 18:41:57 UTC · 3.303°S, 100.362°E

A magnitude 3.9 earthquake struck 179 km SW of Sungai Penuh, Indonesia on Sunday, October 21, 2007, 18:41:57 UTC, at a depth of 35.0 km (shallow).

Magnitude: 3.9; Minor · mb
Depth: 35 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

11 tons of TNT

That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.

Tectonic setting

83 km

from the nearest mapped plate boundary, between the North Andes and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

35 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 M5.9 on November 10, 2007. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 536 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 19 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 241 recorded deaths. The most severe:

2000M7.9
Sumatra: Bengkulu, Enggano
4 Jun 2000 · 248 km away · intensity VI
103 deaths$6 million damage
1995M6.8
Sumatera, Jambi Province
6 Oct 1995 · 184 km away
84 deathsExtreme damage ($25M+)
2007M8.4
Sumatra
12 Sep 2007 · 168 km away
25 deathsSevere damage ($5–24M)tsunami
1914M7.6
Sumatera
25 Jun 1914 · 176 km away
20 deathsLimited damage (under $1M)tsunami
1979M6.6
S Sumatera
15 Dec 1979 · 261 km away
8 deathsSevere damage ($5–24M)
2000M6.7
Southern Sumatera: Lahat
7 Jun 2000 · 225 km away
1 deathModerate damage ($1–5M)

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers