Reviewed by USGSChile81y ago
M6.9 earthquake 52 km W of Diego de Almagro, Chile
Friday, August 2, 1946, 19:18:52 UTC · 26.449°S, 70.568°W
A magnitude 6.9 earthquake struck 52 km W of Diego de Almagro, Chile on Friday, August 2, 1946, 19:18:52 UTC, at a depth of 39.2 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on July 8, 1942.
- Magnitude
- 6.9
- Strong · mw
- Depth
- 39 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
326 kilotons of TNT
That is about 22 times the Hiroshima bomb. It released about 684 times the energy of a magnitude 5.0.
Tectonic setting
114 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
39 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 34 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.594 km ENE of Vallenar, ChileNovember 11, 1922 · 217 km S of this epicenter
- 8.060 km W of Diego de Almagro, ChileDecember 4, 1918 · 8 km W of this epicenter
- 7.583 km NNE of Taltal, ChileJuly 13, 1936 · 197 km N of this epicenter
- 7.550 km WNW of Diego de Almagro, ChileJune 8, 1909 · 33 km N of this epicenter
- 7.4Atacama, ChileApril 18, 1939 · 91 km S of this epicenter
- 7.187 km SSE of Antofagasta, ChileJuly 8, 1942 · 237 km N of this epicenter
- 7.032 km NW of Fiambalá, ArgentinaAugust 3, 1920 · 291 km SE of this epicenter
- 7.0118 km WNW of Vallenar, ChileNovember 7, 1922 · 253 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 23 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 713 recorded deaths. The most severe:
- 1922M8.5
Atacama
11 Nov 1922 · 217 km away · intensity XI
700 deathsSevere damage ($5–24M)tsunami
- 1859M7.6
Chile
5 Oct 1859 · 102 km away · intensity X
10 deathsUnder $1 million damagetsunami
- 1946M7.9
Northern
2 Aug 1946 · 9 km away
2 deathsSevere damage ($5–24M)tsunami
- 1936M7.3
Taltal
13 Jul 1936 · 224 km away
1 deathModerate damage ($1–5M)tsunami
- 1819M8.5
Copiapo
12 Apr 1819 · 111 km away · intensity X
Severe damage ($5–24M)tsunami
- 1819M8.0
Copiapo
4 Apr 1819 · 109 km away
Severe damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.