M4.0 earthquake 102 km S of Sungai Penuh, Indonesia

Monday, April 21, 2008, 20:47:26 UTC · 2.982°S, 101.299°E

A magnitude 4.0 earthquake struck 102 km S of Sungai Penuh, Indonesia on Monday, April 21, 2008, 20:47:26 UTC, at a depth of 100.4 km (intermediate).

Magnitude: 4.0; Light · mb
Depth: 100 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

15 tons of TNT

That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.

Tectonic setting

141 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

100 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 8 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.7 on May 20, 2008. 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 721 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 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 315 recorded deaths. The most severe:

2000M7.9
Sumatra: Bengkulu, Enggano
4 Jun 2000 · 212 km away · intensity VI
103 deaths$6 million damage
1995M6.8
Sumatera, Jambi Province
6 Oct 1995 · 105 km away
84 deathsExtreme damage ($25M+)
2007M6.4
Sumatra: Southern
6 Mar 2007 · 291 km away · intensity VIII
67 deathsSevere damage ($5–24M)
2007M8.4
Sumatra
12 Sep 2007 · 162 km away
25 deathsSevere damage ($5–24M)tsunami
1914M7.6
Sumatera
25 Jun 1914 · 120 km away
20 deathsLimited damage (under $1M)tsunami
1979M6.6
S Sumatera
15 Dec 1979 · 161 km away
8 deathsSevere damage ($5–24M)

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

Nearby trackers