Reviewed by USGSArgentina107y ago
M7.0 earthquake 32 km NW of Fiambalá, Argentina
Tuesday, August 3, 1920, 19:57:22 UTC · 27.475°S, 67.867°W
A magnitude 7.0 earthquake struck 32 km NW of Fiambalá, Argentina on Tuesday, August 3, 1920, 19:57:22 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M8.0 on December 4, 1918.
- Magnitude
- 7.0
- Major · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- 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
529 kilotons of TNT
That is about 35 times the Hiroshima bomb. It released about 1,109 times the energy of a magnitude 5.0.
Tectonic setting
393 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
15 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 4 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.060 km W of Diego de Almagro, ChileDecember 4, 1918 · 298 km W of this epicenter
- 7.550 km WNW of Diego de Almagro, ChileJune 8, 1909 · 300 km NW of this epicenter
- 6.936 km W of Copiapó, ChileSeptember 6, 1910 · 280 km W of this epicenter
- 6.485 km SW of Antofagasta de la Sierra, ArgentinaDecember 4, 1918 · 87 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 21 recorded deaths. The most severe:
- 1899
La Rioja
12 Apr 1899 · 141 km away · intensity VIII
11 deathsModerate damage ($1–5M)
- 1859M7.6
Chile
5 Oct 1859 · 245 km away · intensity X
10 deathsUnder $1 million damagetsunami
- 1819M8.0
Copiapo
4 Apr 1819 · 240 km away
Severe damage ($5–24M)
- 1819M8.0
Copiapo
3 Apr 1819 · 240 km away
Moderate damage ($1–5M)
- 1796M7.7
Copiapo, Vallenar, Huasco, Coquimbo
30 Mar 1796 · 245 km away · intensity XI
Moderate damage ($1–5M)
- 1851M7.2
Copiapo
26 May 1851 · 245 km away · intensity X
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.