M8.5 earthquake 94 km ENE of Vallenar, Chile

Saturday, November 11, 1922, 04:32:51 UTC · 28.293°S, 69.852°W

A magnitude 8.5 earthquake struck 94 km ENE of Vallenar, Chile on Saturday, November 11, 1922, 04:32:51 UTC, at a depth of 70.0 km (intermediate). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 8.5; Great · mw
Depth: 70 km; Intermediate
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: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

85 megatons of TNT

That is about 5,632 times the Hiroshima bomb. It released about 177,828 times the energy of a magnitude 5.0.

Tectonic setting

215 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: intermediate

70 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 400 km

USGS lists 3 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M6.8 on November 17, 1922. 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 10 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 20 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 721 recorded deaths. The most severe:

1922M8.5
Atacama
11 Nov 1922 · 0 km away · intensity XI
700 deathsSevere damage ($5–24M)tsunami
1899
La Rioja
12 Apr 1899 · 147 km away · intensity VIII
11 deathsModerate damage ($1–5M)
1859M7.6
Chile
5 Oct 1859 · 116 km away · intensity X
10 deathsUnder $1 million damagetsunami
1819M8.5
Copiapo
12 Apr 1819 · 217 km away · intensity X
Severe damage ($5–24M)tsunami
1819M8.0
Copiapo
4 Apr 1819 · 109 km away
Severe damage ($5–24M)
1918M7.8
Copiapo
4 Dec 1918 · 279 km away
Severe damage ($5–24M)tsunami

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

Nearby trackers