M9.5 earthquake 1960 Great Chilean Earthquake (Valdivia Earthquake)

Sunday, May 22, 1960, 19:11:20 UTC · 38.143°S, 73.407°W

A magnitude 9.5 earthquake struck 1960 Great Chilean Earthquake (Valdivia Earthquake) on Sunday, May 22, 1960, 19:11:20 UTC, at a depth of 25.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 9.5; Epic · mw
Depth: 25 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: IX; Violent (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

2682 megatons of TNT

That is about 178,098 times the Hiroshima bomb. It released about 5,623,413 times the energy of a magnitude 5.0.

Tectonic setting

109 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

25 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 400 km

USGS lists 11 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M7.0 on June 20, 1960. 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 27 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 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 32,416 recorded deaths. The most severe:

1939M8.3
Chillan
25 Jan 1939 · 234 km away · intensity X
30,000 deaths$920 million damagetsunami
1960M9.5
Puerto Montt, Valdivia
22 May 1960 · 0 km away · intensity XII
2,226 deaths$1.0 billion damagetsunami
1751M8.5
Concepcion, Chillan, Talca, Tutuben, Curico
25 May 1751 · 214 km away · intensity XI
65 deathsSevere damage ($5–24M)tsunami
1949M7.3
Angol, Traiguen
20 Apr 1949 · 18 km away
57 deathsModerate damage ($1–5M)tsunami
1835M8.2
Concepcion
20 Feb 1835 · 150 km away · intensity XI
53 deathsExtreme damage ($25M+)tsunami
1953M7.6
Chillan, Concepcion
6 May 1953 · 200 km away · intensity X
9 deaths$500 million damagetsunami

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

Nearby trackers