M7.2 earthquake 47 km NW of Cauquenes, Chile

Sunday, December 2, 1928, 04:20:26 UTC · 35.712°S, 72.740°W

A magnitude 7.2 earthquake struck 47 km NW of Cauquenes, Chile on Sunday, December 2, 1928, 04:20:26 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M7.7 on December 1, 1928.

Magnitude: 7.2; Major · mw
Depth: 30 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VII; Very strong (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

1.1 megatons of TNT

That is about 70 times the Hiroshima bomb. It released about 2,213 times the energy of a magnitude 5.0.

Tectonic setting

105 km

from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

30 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 200 km

USGS lists 5 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.7 on December 20, 1928. 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 14 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 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 403 recorded deaths. The most severe:

1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 104 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
1751M8.5
Concepcion, Chillan, Talca, Tutuben, Curico
25 May 1751 · 159 km away · intensity XI
65 deathsSevere damage ($5–24M)tsunami
1835M8.2
Concepcion
20 Feb 1835 · 127 km away · intensity XI
53 deathsExtreme damage ($25M+)tsunami
1898M6.5
Concepcion
23 Jul 1898 · 127 km away · intensity VIII
6 deathsModerate damage ($1–5M)tsunami
1871M7.5
Central
25 Mar 1871 · 82 km away
Severe damage ($5–24M)tsunami
1851M7.1
Valparaiso
2 Apr 1851 · 292 km away · intensity VIII
Severe damage ($5–24M)tsunami

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

Nearby trackers