Reviewed by USGSChile109y ago
M8.0 earthquake 60 km W of Diego de Almagro, Chile
Wednesday, December 4, 1918, 11:47:51 UTC · 26.462°S, 70.650°W
A magnitude 8.0 earthquake struck 60 km W of Diego de Almagro, Chile on Wednesday, December 4, 1918, 11:47:51 UTC, at a depth of 40.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 8.0
- Great · mw
- Depth
- 40 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: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
16 megatons of TNT
That is about 1,037 times the Hiroshima bomb. It released about 32,734 times the energy of a magnitude 5.0.
Tectonic setting
106 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
40 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 1 M2.5+ earthquake within 400 km in the following 30 days; the largest was M6.4 on December 4, 1918. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 4 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.550 km WNW of Diego de Almagro, ChileJune 8, 1909 · 37 km NE of this epicenter
- 6.9178 km W of Taltal, ChileMay 24, 1913 · 185 km NW of this epicenter
- 6.936 km W of Copiapó, ChileSeptember 6, 1910 · 107 km S of this epicenter
- 6.697 km SW of Antofagasta, ChileAugust 5, 1907 · 235 km N of this epicenter
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 10 recorded deaths. The most severe:
- 1859M7.6
Chile
5 Oct 1859 · 103 km away · intensity X
10 deathsUnder $1 million damagetsunami
- 1819M8.5
Copiapo
12 Apr 1819 · 103 km away · intensity X
Severe damage ($5–24M)tsunami
- 1819M8.0
Copiapo
4 Apr 1819 · 110 km away
Severe damage ($5–24M)
- 1918M7.8
Copiapo
4 Dec 1918 · 62 km away
Severe damage ($5–24M)tsunami
- 1819M8.0
Copiapo
3 Apr 1819 · 110 km away
Moderate damage ($1–5M)
- 1796M7.7
Copiapo, Vallenar, Huasco, Coquimbo
30 Mar 1796 · 103 km away · intensity XI
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.