Reviewed by USGSChile94y ago
M7.3 earthquake 34 km S of Iquique, Chile
Thursday, February 23, 1933, 08:09:19 UTC · 20.521°S, 70.192°W
A magnitude 7.3 earthquake struck 34 km S of Iquique, Chile on Thursday, February 23, 1933, 08:09:19 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.3 on June 6, 1915.
- Magnitude
- 7.3
- Major · mw
- Depth
- 35 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
1.3 megatons of TNT
That is about 83 times the Hiroshima bomb. It released about 2,630 times the energy of a magnitude 5.0.
Tectonic setting
109 km
from the nearest mapped plate boundary, between the Altiplano and South American 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 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 13 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.3136 km WSW of Challapata, BoliviaJune 6, 1915 · 269 km NE of this epicenter
- 7.278 km SW of Colchani, BoliviaOctober 4, 1910 · 278 km E of this epicenter
- 7.064 km NNE of Antofagasta, ChileNovember 20, 1928 · 293 km S of this epicenter
- 6.9119 km W of Iquique, ChileSeptember 15, 1911 · 121 km W of this epicenter
- 6.925 km ENE of Arica, ChileAugust 30, 1906 · 241 km N of this epicenter
- 6.9181 km W of Iquique, ChileAugust 25, 1916 · 181 km W of this epicenter
- 6.987 km NNW of Iquique, ChileDecember 26, 1906 · 116 km N of this epicenter
- 6.881 km WSW of Calama, ChileDecember 23, 1916 · 256 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 36 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 28,085 recorded deaths. The most severe:
- 1868M8.5
Arica
13 Aug 1868 · 230 km away · intensity XI
25,000 deaths$300 million damagetsunami
- 1877M8.3
Off North Coast
10 May 1877 · 113 km away · intensity XI
2,385 deaths$2 million damagetsunami
- 1833M7.7
Peru: Tacna; Chile: Arica
18 Sep 1833 · 267 km away · intensity VIII
700 deathsSevere damage ($5–24M)tsunami
- 1878M7.9
Tarapaca
23 Jan 1878 · 68 km away · intensity VIII
Severe damage ($5–24M)tsunami
- 1871M7.3
Chile
5 Oct 1871 · 36 km away · intensity X
Severe damage ($5–24M)tsunami
- 1705
Chile: Arica
26 Nov 1705 · 214 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.