M6.5 earthquake 157 km SSW of Pagar Alam, Indonesia

Thursday, February 19, 1931, 17:40:36 UTC · 5.242°S, 102.513°E

A magnitude 6.5 earthquake struck 157 km SSW of Pagar Alam, Indonesia on Thursday, February 19, 1931, 17:40:36 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.6 on February 14, 1931.

Magnitude: 6.5; Strong · mw
Depth: 35 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VI; Strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

71 kilotons of TNT

That is about 5 times the Hiroshima bomb. It released about 150 times the energy of a magnitude 5.0.

Tectonic setting

151 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: 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 100 km

USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 22 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 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 20 recorded deaths. The most severe:

1914M7.6
Sumatera
25 Jun 1914 · 165 km away
20 deathsLimited damage (under $1M)tsunami
1770M7.0
Sumatra:
1770 · 63 km away
Severe damage ($5–24M)tsunami
1931M7.4
Sw. Sumatra
25 Sep 1931 · 38 km away · intensity VIII
Limited damage (under $1M)tsunami
1818M7.0
Sumatra: Bengkulu
18 Mar 1818 · 178 km away · intensity IX
Limited damage (under $1M)tsunami
1896M6.8
Sw. Sumatra, Java
10 Oct 1896 · 194 km away
Limited damage (under $1M)tsunami

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

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